Microorganism

Biochem Pharmacol, 1998 May 1, 55(9), 1339 - 46
Ras, superoxide and signal transduction; Irani K et al.; The superoxide anion has been associated with the bactericidal activity of phagocytes . Produced by an enzymatic complex, NADPH oxidase, bactericidal superoxide is released within phagolysosomes where bacteria are being degraded . The activity of NADPH oxidase is regulated by Rac, a small GTP binding protein of the Ras family . Recent evidence indicates that, in addition to its bactericidal activity, superoxide seems to function as a signal-transduction messenger, mediating the downstream effects of Ras and Rac in nonphagocytic cells . As such, superoxide contributes to the unchecked proliferation of Ras-transformed cells . In the nitric oxide (NO) system, low concentrations of NO transduce signals within vessels and neurons, while high concentrations of NO can produce damage to cells and microorganisms . By analogy, superoxide and probably other oxidants serve as messengers at low concentrations, while larger amounts are required for inducing damage . The activity of oxidants as messengers opens new avenues for pharmacological intervention against Ras-mediated pathways in mammalian cells.

Scand J Immunol, 1999 Feb, 49(2), 193 - 6
Mannan-binding lectin deficiency is associated with unexplained recurrent miscarriage; Christiansen OB et al.; Mannan-binding lectin (MBL) is a plasma protein which, upon binding to microbial carbohydrate structures, elicits activation of the complement system . The level of MBL is genetically determined . It has been reported that the frequency of low plasma levels of MBL is increased in patients with unexplained recurrent miscarriages (RM) . In the present study plasma MBL levels were determined in 146 Danish women with RM and 41 of their husbands together with 49 Scottish RM women and 41 of their husbands . In both countries MBL levels were also investigated in a total of 444 controls . Based on the control data, a cut-off MBL level < 50 ng/ml was selected to define MBL deficiency . The typical odds ratio for MBL deficiency among female patients in the two populations was 1.68 (95% confidence limits 1.01-2.80, P<0.05) whereas it was 1.57 (95% confidence limits 0.72-3.42, not significant) for the male partners of the patients . There was a significant correlation between the frequency of MBL deficiency in RM women and the number of previous miscarriages (P < 0.01), whereas no such correlation was found in the husbands . The results indicate that maternal MBL deficiency is associated with RM . Maternal MBL deficiency might impair the immune defence against microorganisms at the feto-maternal interface.

Ann Intern Med, 1999 Jan 19, 130(2), 126 - 30
Compliance with handwashing in a teaching hospital . Infection Control Program; Pittet D et al.; BACKGROUND: Transmission of microorganisms from the hands of health care workers is the main source of cross-infection in hospitals and can be prevented by handwashing . OBJECTIVE: To identify predictors of noncompliance with handwashing during routine patient care . DESIGN: Observational study . SETTING: Teaching hospital in Geneva, Switzerland . PARTICIPANTS: Nurses (66%), physicians (10%), nursing assistants (13%), and other health care workers (11%) . MEASUREMENTS: Compliance with handwashing . RESULTS: In 2834 observed opportunities for handwashing, average compliance was 48% . In multivariate analysis, noncompliance was higher among physicians (odds ratio {OR}, 2.8 {95% CI, 1.9 to 4.1}), nursing assistants (OR, 1.3 {CI, 1.0 to 1.6}), and other health care workers (OR, 2.1 {CI, 1.4 to 3.2}) than among nurses and was lowest on weekends (OR, 0.6 {CI, 0.4 to 0.8}) . Noncompliance was higher in intensive care than in internal medicine units (OR, 2.0 {CI, 1.3 to 3.1}), during procedures that carry a high risk for contamination (OR, 1.8 {CI, 1.4 to 2.4}), and when intensity of patient care was high (compared with < or = 20 opportunities for handwashing per hour of care, 21 to 40 opportunities: OR, 1.3 {CI, 1.0 to 1.7}; 41 to 60 opportunities: OR, 2.1 {CI, 1.5 to 2.9}; and > 60 opportunities: OR, 2.1 {CI, 1.3 to 3.5}) . CONCLUSIONS: Compliance with handwashing was moderate . Variation across hospital ward and type of health care worker suggests that targeted educational programs may be useful . Even though observational data cannot prove causality, the association between noncompliance and intensity of care suggests that understaffing may decrease quality of patient care.

J Chromatogr B Biomed Sci Appl, 1999 Feb 5, 722(1-2), 263 - 78
Methods for the differentiation of microorganisms; Busch U et al.; Advances in analytical and diagnostic assays based on novel nucleic acid analyses techniques have revolutionized the application of molecular differentiation of microorganisms . Phenotypic typing schemes are now broadly supplemented by new genotyping methods which allow a more refined and detailed differentiation of closely related microorganisms, bacterial strains, isolates and pathogens on the DNA level . Bio-, sero- and phagetyping, antibiotic susceptibility tests, immunoblotting as well as multilocus enzyme- or polyacrylamide gel electrophoresis are now supported by the analysis of plasmid or chromosomal DNA restriction profiles, ribotyping, pulsed-field gel electrophoresis and polymerase- or ligase-chain reaction-based methods or direct sequencing technique to differentiate microorganisms . Some of these molecular techniques are also used in the field of virology to analyse and differentiate closely related sub- or genotypes . Few examples for the analysis and investigation of these usually small genomes will also be given.

Curr Opin Microbiol, 1998 Dec, 1(6), 643 - 8
Two-component signal transduction systems in eukaryotic microorganisms; Loomis WF et al.; Conserved signal transduction pathways that use phosphorelay from histidine kinases through an intermediate transfer protein (H2) to response regulators have been found in a variety of eukaryotic microorganisms . Several of these pathways are linked to mitogen-activated protein kinase cascades . These networks control different physiological responses including osmoregulation, cAMP levels and cellular morphogenesis.

Curr Opin Microbiol, 1998 Jun, 1(3), 278 - 85
The value of microbial diversity; Hunter-Cevera JC; In the past few years, due to the use of molecular methods, our knowledge of microbial diversity has increased dramatically, not only from a phylogenetic and taxonomic perspective but also from an ecological basis . We now know that microorganisms exist in every conceivable place on Earth, even in extreme environments . Temperature may be the only limitation as to where they can and cannot exist and/or function . As more small subunit rDNA sequence information becomes available there is a real need to start turning the information into knowledge that can be applied to better elucidate and understand structure-function relationships within ecosystems, develop new culturing methods, and discover new products and processes . It has been stated on numerous occasions that the 21(st) century is the century for biology . Within that context, we must address the real value of microbial diversity.

Curr Opin Microbiol, 1998 Jun, 1(3), 319 - 29
Combinatorial biosynthesis for new drug discovery; Hutchinson CR; Combinatorial biosynthesis involves interchanging secondary metabolism genes between antibiotic-producing microorganisms to create unnatural gene combinations or hybrid genes if only part of a gene is exchanged . Novel metabolites can be made by both approaches, due to the effect of a new enzyme on a metabolic pathway or to the formation of proteins with new enzymatic properties . The method has been particularly successful with polyketide synthase (PKS) genes: derivatives of medically important macrolide antibiotics and unusual polycyclic aromatic compounds have been produced by novel combinations of the type I and type II PKS genes, respectively . Recent extensions of the approach to include deoxysugar biosynthesis genes have expanded the possibilities for making new microbial metabolites and discovering valuable drugs through the genetic engineering of bacteria.

Curr Opin Microbiol, 1998 Jun, 1(3), 291 - 5
Barophiles: deep-sea microorganisms adapted to an extreme environment; Horikoshi K; The deep-sea environment is characterized by high pressure and low temperature but in the vicinity of hydrothermal vents regions of extremely high temperature exist . Deep-sea microorganisms have specially adapted features that enable them to live and grow in this extreme environment . Recent research on the physiology and molecular biology of deep-sea barophilic bacteria has identified pressure-regulated operons and shown that microbial growth is influenced by the relationship between temperature and pressure in the deep-sea environment.

Curr Opin Microbiol, 1998 Jun, 1(3), 352 - 8
In situ methods for assessment of microorganisms and their activities; Amann R et al.; Recent technical developments in the field of molecular biology and microsensors are beginning to enable microbiologists to study the abundance, localization and activity of microorganisms in situ . The various new methods on their own bear high potential but it is the combination of studies on structure and function of microbial communities that will yield the most detailed insights in the way microorganisms operate in nature.

Biochem Biophys Res Commun, 1999 Mar 5, 256(1), 231 - 4
Metabolic properties of normal and mutant mannan-binding proteins in mouse plasma; Naito H et al.; Human mannan-binding protein (MBP) is a serum lectin involved in innate immunity . MBP activates the complement pathway through its interaction with mannose-rich carbohydrates on various microorganisms and a common opsonic defect has been shown to be associated with a low serum concentration of MBP . This low serum concentration is closely associated with a single base mutation in codon 52, 54 or 57 of the human MBP gene, which results in a change of Arg52 to Cys, Gly54 to Asp, or Gly57 to Gln, respectively, in the collagen-like region of the molecule and prevents the formation of higher oligomers . However, the mechanism underlying the low serum concentration in such patients is completely unknown . The levels of protein synthesis and secretion of the normal and mutant MBPs seem to be similar according to our previous in vitro results . In this study, we examined the plasma clearance of the normal and mutant human (Gly54Asp) MBPs in mice, and found that the half-life of the mutant MBP is about half that of the normal MBP, explaining in part the difference in the plasma levels between the two types of MBP .

Scand J Infect Dis, 1998, 30(5), 495 - 9
Low levels of IgG antibodies against pneumocystis carinii among HIV-infected patients; Laursen AL et al.; IgG antibodies against Pneumocystis carinii (P . carinii) were detected by an ELISA method using urea-extracted material from human and rat P . carinii as the antigen . Carbohydrate formed a major part of the antigen responsible for reactivity in the ELISA assay, since periodate treatment reduced the reactivity of most sera tested . Cross-reactivity between human and rat P . carinii was detected . However, human serum recognized antigens specific for human P . carinii . With the ELISA method IgG antibody levels were compared between blood donors (n = 40), asymptomatic HIV-antibody positive patients (n = 30) and AIDS patients with (n=22) and without previous P . carinii pneumonia (PCP) (n=21) . HIV-infected patients had significantly lower antibody reactivity against the microorganism compared with blood donors . Among HIV-antibody positive patients the highest antibody reactivity was seen in PCP patients . The antibody response to PCP was impaired, since an equal number of patients had an increase and a decrease in antibody reactivity . In conclusion, carbohydrate formed an important part of the P . carinii immunogenic antigen . Cross-reactivity between rat and human P . carinii was demonstrated, but reactivity was somewhat lower using antigen from rats . The antibody level was lower in HIV-infected patients and the ability to mount an antibody response to the infection was impaired, suggesting that the poor antibody response may contribute to the liability of HIV-infected patients to have PCP.

Scand J Infect Dis, 1998, 30(5), 481 - 3
A blood micro-culture system for the diagnosis of bacteremia in pediatric patients; Solorzano-Santos F et al.; The aim of this study was to evaluate the utility of a volume-modified blood culture system to diagnose bacteremia in newborns and infants . A total of 793 paired blood cultures, obtained from 464 patients (173 newborns and 291 infants), were analyzed . Vacutainer tubes containing 18 ml supplemented peptone broth sodium-polyanethol-sulfonate were used as the gold standard, in comparison with a blood micro-culture system containing 1.8 ml of the broth . Prior to antibiotic treatment, 2.2 ml of blood was obtained from each patient; 0.2 ml was inoculated in a blood micro-culture tube and 2 ml in a routine tube . Sensitivity, specificity and predictive values were calculated . Microorganisms were isolated in 153 standard blood culture tubes and 151 blood micro-culture tubes . The sensitivity of the blood micro-culture system was 95%, specificity 99% and positive and negative predictive values 96% and 99% respectively . The sensitivity and specificity of blood micro-culture in neonates and infants is high . We recommend that this system be used for the diagnosis of bacteremia in newborns and infants in laboratories where manual systems are still in use.

Biosci Biotechnol Biochem, 1999 Jan, 63(1), 1 - 9
Microbial desulfurization of organic sulfur compounds in petroleum; Ohshiro T et al.; Sulfur removal from petroleum is important from the standpoint of the global environment because the combustion of sulfur compounds leads to the production of sulfur oxides, which are the source of acid rain . As the regulations for sulfur in fuels become more stringent, the existing chemical desulfurizations are coming inadequate for the "deeper desulfurization" to produce lower-sulfur fuels without new and innovative processes . Biodesulfurization is rising as one of the candidates . Several microorganisms were found to desulfurize dibenzothiophene (DBT), a representative of the organic sulfur compounds in petroleum, forming a sulfur-free compound, 2-hydroxybiphenyl . They are promising as biocatalysts in the microbial desulfurization of petroleum because without assimilation of the carbon content, they remove only sulfur from the heterocyclic compounds which is refractory to conventional chemical desulfurization . Both enzymological and molecular genetic studies are now in progress for the purpose of obtaining improved desulfurization activity of organisms . The genes involved in the sulfur-specific DBT desulfurization were identified and the corresponding enzymes have been investigated . From the practical point of view, it has been proved that the microbial desulfurization proceeds in the presence of high concentrations of hydrocarbons, and more complicated DBT analogs are also desulfurized by the microorganisms . This review outlines the progress in the studies of the microbial desulfurization from the basic and practical point of view.

Khirurgiia (Mosk), 1999, (1), 12 - 3
{Complications of sorption-application therapy of purulent wounds}; Pavlov VV et al.; A retrospective analysis of 187 case records was made for elucidation of the frequency of development of complications in sorption-applicational treatment of festering wounds . It was revealed that late after strewing sterile sorbent into the wound in 6.4% of patients the development of fistulas and going out of preparation granules though fistula occurred . It is concluded, that sorbent's granules incapsulate together with living microorganisms adsorbed on their surface . For prevention of this complication the corbent is recommended to be introduced into the wound in small porous containers, which provide quick replacement of the preparation during wound dressing and its complete elimination in the end of healing.

PDA J Pharm Sci Technol, 1998 Nov-Dec, 52(6), 344 - 5
Neutralization of beta-lactam antibiotics in an environmental monitoring medium; Winely C et al.; The neutralizing ability of Difco Bacto Penase, BBL Penicillinase, and Genzyme beta-lactamase for penicillin G, oxacillin, cephalothin, cefazolin, ceftazidime, ceftriaxone, cefotaxime, imipenem, and meropenem was determined in an agar medium . Trypticase soy agar plates (20 mL) containing 200 MU/L Difco Penase, 200 MU/L BBL Penicillinase, or 2 vials/L of Genzyme beta-lactamase were dosed with 20, 50, and 100 micrograms of each antibiotic and then inoculated (50-100 CFU/plate) with a susceptible microorganism . Percentage recoveries of the organism were calculated after incubation . Genzyme beta-lactamase effectively neutralized 100 micrograms of all the antibiotics except ceftazidime (32% recovery with 20 micrograms) . The two penicillinases effectively neutralized 100 micrograms of penicillin G, oxacillin, cephalothin, and cefazolin; were slightly effective against ceftriaxone and cefotaxime (20-57% recovery with 20 micrograms); and totally ineffective against ceftazidime, imipenem, and meropenem . This investigation resulted in a useful procedure for qualifying and/or selecting a beta-lactamase for use in environmental monitoring medium to neutralize a particular beta-lactam.

Appl Environ Microbiol, 1999 Mar, 65(3), 893 - 7
Relationship between glycosyl hydrolase inventory and growth physiology of the hyperthermophile Pyrococcus furiosus on carbohydrate-based media; Driskill LE et al.; Utilization of a range of carbohydrates for growth by the hyperthermophile Pyrococcus furiosus was investigated by examining the spectrum of glycosyl hydrolases produced by this microorganism and the thermal labilities of various saccharides . Previously, P . furiosus had been found to grow in batch cultures on several alpha-linked carbohydrates and cellobiose but not on glucose or other beta-linked sugars . Although P . furiosus was not able to grow on any nonglucan carbohydrate or any form of cellulose in this study (growth on oat spelt arabinoxylan was attributed to glucan contamination of this substrate), significant growth at 98 degrees C occurred on beta-1,3- and beta-1,3-beta-1,4-linked glucans . Oligosaccharides generated by digestion with a recombinant laminarinase derived from P . furiosus were the compounds that were most effective in stimulating growth of the microorganism . In several cases, periodic addition of beta-glucan substrates to fed-batch cultures limited adverse thermochemical modifications of the carbohydrates (i.e., Maillard reactions and caramelization) and led to significant increases (as much as two- to threefold) in the cell yields . While glucose had only a marginally positive effect on growth in batch culture, the final cell densities nearly tripled when glucose was added by the fed-batch procedure . Nonenzymatic browning reactions were found to be significant at 98 degrees C for saccharides with degrees of polymerization (DP) ranging from 1 to 6; glucose was the most labile compound on a mass basis and the least labile compound on a molar basis . This suggests that for DP of 2 or greater protection of the nonreducing monosaccharide component may be a factor in substrate availability . For P . furiosus, carbohydrate utilization patterns were found to reflect the distribution of the glycosyl hydrolases which are known to be produced by this microorganism.

Antimicrob Agents Chemother, 1999 Mar, 43(3), 714 - 6
Lactic acid polymers as biodegradable carriers of fluoroquinolones: an in vitro study; Kanellakopoulou K et al.; A biodegradable polymer of DL-dilactide that facilitates release of ciprofloxacin or pefloxacin at levels exceeding MICs for the causative microorganisms of chronic osteomyelitis is described . Duration and peak of release were found to depend on the molecular weight of the polymer . Its characteristics make it promising for treating chronic bone infections.

Wien Klin Wochenschr, 1998 Dec 23, 110(24), 859 - 62
Genetic studies in Borrelia burgdorferi; Rosa P et al.; Borrelia burgdorferi, the agent of Lyme disease, has recently joined a growing number of micro-organisms for which the entire genomic sequence is known . Despite this wealth of information, little is known about the contribution of specific spirochetal components to the pathogenesis of Lyme disease or their function in the normal life cycle of the organism . This discrepancy is due in part to the lack of a well-developed genetic system in B . burgdorferi, which in turn can be attributed to its relatively recent isolation and the dissimilarity of Borrelia from other genetically tractable bacteria . We are interested in several plasmid-encoded gene products in B . burgdorferi that may play a role in sensing and adaptation to the different environments the spirochete encounters as it completes an infectious cycle between the tick vector and the mammalian host . We are developing genetic tools with which to test the roles of specific B . burgdorferi gene products in the transmission cycle in an animal model of Lyme disease . We have demonstrated targeted gene inactivation by allelic exchange, using the gyrBr gene encoding coumermycin-resistant topoisomerase as a selectable marker . Spirochetes are transformed by electroporation and coumermycin-resistant colonies are screened by PCR for allelic exchange at the targeted locus . We have successfully inactivated several genes of interest in the type strain B31 . We are investigating the utility of additional antibiotic resistance genes as selectable markers in B . burgdorferi . Targeted gene inactivation is a powerful tool with which to investigate the role of particular proteins in the basic biology and virulence of a pathogenic microorganism . We have made significant advances in our ability to genetically manipulate B . burgdorferi in order to address these issues . However, the available methods are incomplete and far from routine . We are currently improving existing methods as well as developing additional genetic tools with which to augment genetic studies in B . burgdorferi.

Wien Klin Wochenschr, 1998 Dec 23, 110(24), 856 - 8
Natural history of Borrelia burgdorferi sensu lato; Gern L et al.; Lyme borreliosis is a zoonosis: its causative agent, B: burgdorferi, circulates between ticks and a large range of vertebrates . Identification of the hosts which are responsible for the infection of the vectors is extremely important to determine the potential risk of infection in an habitat . Various small mammals and bird species are considered reservoirs for the Lyme disease spirochetes . Grey and red squirrels, hedgehogs as well as hares and rabbits can develop an infection and transmit B . burgdorferi sensu lato to feeding ticks . In Eurasian endemic areas, many different Borrelia species circulate between ticks and vertebrate hosts . Studies have shown that European and Asian genospecies are associated with specific groups of vertebrate hosts, such as B . valaisiana and B . garinii with birds, B . afzelii with small mammals and B . burgdorferi ss and B . afzelii with red squirrels . However, such associations are not always observed as in Japan where B . garinii, B . afzelii and unidentified Borrelia species are found in small mammals . Some enzootic cycles involving tick species which do not feed at all on humans or which rarely feed on humans have been described in Europe and USA . It is likely that many existing enzootic foci have yet to be discovered . The circulation of B . burgdorferi in silent foci does not have important implications for human health, but it demonstrates the complexity of the ecology of this microorganism and the variety of ecological niches this spirochete can occupy.

J Food Prot, 1999 Feb, 62(2), 128 - 32
Inhibition of growth of Escherichia coli O157:H7 in fresh radish (Raphanus sativus L.) sprout production by calcinated calcium; Bari ML et al.; The inhibitory effect of calcinated calcium on the growth of Escherichia coli O157:H7 during fresh radish (Raphanus sativus L.) sprout production was studied . It was revealed that the addition of 0.4% (wt/vol) calcinated calcium into radish sprouting medium which was artificially contaminated with E . coli O157:H7 (3.0 to 3.2 log CFU/ml) completely inhibited the growth or inactivated the microorganism . When radish seed extract was used instead of radish sprout production, the same extent of growth inhibition or inactivation was observed with much lower amounts (0.07%) of calcinated calcium under similar experimental conditions . The findings suggested that calcinated calcium may be useful to control E . coli O157:H7 contamination during the production of radish sprouts.

Yeast, 1999 Jan 15, 15(1), 23 - 33
Saccharomyces cerevisiae IRR1 protein is indirectly involved in colony formation; Kurlandzka A et al.; The ability of a microorganism to adhere to a solid support and to initiate a colony is often the first stage of microbial infections . To date, studies on S . cerevisiae cell-cell and cell-solid support interactions concerned only cell agglutination during mating and flocculation . Colony formation has not been studied before probably because this species is not pathogenic . However, S . cerevisiae can be a convenient model to study this process, thanks to well-developed genetics and the full knowledge of its nucleotide sequence . A preliminary characterization of the recently cloned essential IRR1 gene indicated that it may participate in cell-cell/substrate interactions . Here we show that lowering the level of expression of IRR1 (after fusion with a regulatory catalase A gene promoter) affects colony formation and disturbs zygote formation and spore germination . All these processes involve cell-cell or cell-solid support contacts . The IRR1 protein is localized in the cytosol as verified by immunofluorescence microscopy, and confirmed by cell fractionation and Western blotting . This indicates that Irr1p is not directly involved in the cell-solid support adhesion, but may be an element of a communication pathway between the cell and its surroundings.

Yeast, 1999 Jan 15, 15(1), 11 - 22
Cloning, sequence analysis and overexpression of a Saccharomyces cerevisiae endopolygalacturonase-encoding gene (PGL1); Gognies S et al.; Only a few yeast strains produce pectin-degrading enzymes such as pectin esterases and depolymerases (hydrolases and lyases) . Strain SCPP is the only known Saccharomyces strain to produce these pectinases . One of these pectolytic enzymes . PGL1-encoded endopolygalacturonase (EC 3.2.1.15), hydrolyses the alpha-1,4-glycosidic bonds within the rhamnogalacturonan chains in pectic substances . This paper presents the cloning and sequencing of the first S . cerevisiae gene involved in pectin degradation . Few differences were found between the two deduced amino acid sequences encoded by PGL1-1 from a pectolytic (PG+) strain (SCPP) and PGL1-2 from a non-pectolytic (PG-) strain (X2180-1B) . Similarities were found with other polygalacturonases from plants and other microorganisms . Of the two S . cerevisiae genes, only the one isolated from strain SCPP was able, by overexpression, to confer endopolygalacturonase activity to a laboratory strain of S . cerevisiae . Overexpression of PGL1-1 gene in a non-pectolytic strain resulted in halo formation on polygalacturonic acid-containing agar plates stained with ruthenium red.

Circulation, 1999 Feb 23, 99(7), 879 - 82
Detection of Chlamydia pneumoniae but not cytomegalovirus in occluded saphenous vein coronary artery bypass grafts; Bartels C et al.; BACKGROUND: A causal relation between atherosclerosis and chronic infection with Chlamydia pneumoniae and/or cytomegalovirus (CMV) has been suggested . Whether the unresolved problem of venous coronary artery bypass graft occlusion is related to infection with C pneumoniae and/or CMV has not been addressed . METHODS AND RESUTLS: Thirty-eight occluded coronary artery vein grafts and 20 native saphenous veins were examined . Detection of C pneumoniae DNA was performed by use of nested polymerase chain reaction (PCR) . Homogenisates from the specimen were cultured for identification of viable C pneumoniae . Both conventional PCR and quantitative PCR for detection of CMV DNA were applied . Differential pathological changes (degree of inflammation, smooth muscle cell proliferation {MIB-1}) were determined and correlated to the detection of both microorganisms . C pneumoniae DNA could be detected in 25% of occluded vein grafts . Viable C pneumoniae was recovered from 16% of occluded vein grafts . Except for 1 native saphenous vein, all control vessels were negative for both C pneumoniae detection and culture . All pathological and control specimens were negative for CMV DNA detection . Pathological changes did not correlate with C pneumoniae detection . CONCLUSIONS: Occluded aorto-coronary venous grafts harbor C pneumoniae but not CMV . The detection of C pneumoniae in occluded vein grafts warrants further investigation.

J Chromatogr B Biomed Sci Appl, 1999 Jan 8, 721(1), 31 - 7
Surface characterization and on-line activity measurements of microorganisms by capillary zone electrophoresis; Torimura M et al.; Capillary zone electrophoresis (CZE) was applied to the electrophoretic characterization for microorganisms . The electrophoretic peaks detected using light scattering phenomena were characteristic of the microorganisms used . The electrophoretic mobility (mu) evaluated by CZE was in good agreement with that obtained by classical electrophoresis of microorganisms . The migration time was reproducible and depended on the ionic strength (I) . Analysis of the mu vs . I relationship provided information regarding the charge density and the hardness of the microbial cell surface . The redox enzymatic activity of microorganisms was also evaluated by CZE using a running buffer containing a corresponding substrate and an appropriate exogenous electron acceptor . A decrease in the concentration of the electron acceptor due to microbial activity can be simultaneously monitored during the electrophoretic process without significant modification of the CZE instrument . Effects of some chemical treatments of microbial cells were also studied using this technique.

J Clin Lab Anal, 1999, 13(1), 1 - 4
Reliability of low-avidity IgG and of IgA in the diagnosis of primary infection by rubella virus with adaptation of a commercial test; Gutierrez J et al.; The detection of IgA and low-avidity IgG and antibodies in serum is a potentially useful marker of recent infection by a microorganism . We studied the reliability of IgG avidity and presence of IgA for the diagnosis of recent acute infection by rubella virus . Low-avidity IgG (Avy-EIA test) was determined with a modified commercial test using 8 molar urea (indirect ELISA, DiaSorin, Italy) and IgA was determined with a homemade indirect ELISA test . Twenty-five patients with recent primary infection by rubella virus (group I) and 50 healthy subjects (group II) were studied . In group I low-avidity IgG varied between 100 and 0% (67.3+/-21.8%); IgA was present in 24 patients (96%) . In group II low-avidity IgG varied from 50.4 to 0% (19.8+/-16.9%) . IgA was present in 2 subjects (4%) . The sensitivity of the Avi-EIA and the IgA test was 92 and 96%, respectively; specificity was 100 and 96%, respectively . We conclude that both low-avidity IgG and IgA tests are helpful and reliable for the diagnosis of recent primary infection.

Phys Rev A, 1991 Oct 15, 44(8), 5279 - 91
Evolution of bioconvective patterns in variable gravity; Noever DA; Measurements are reported of the evolution of bioconvective patterns in shallow, dense cultures of microorganisms subjected to varying gravity . Various statistical properties of this random, quasi-two-dimensional structure have been found: Aboav's law is obeyed, the average vertex angles follow predictions for regular polygons, and the area of a pattern varies linearly with its number of sides . As gravity varies between 1 g and 1.8g (g = 9.8 m s-1), these statistical properties continue to hold despite a tripling of the number of polygons and a reduced average polygon dimension by a third . This work compares with experiments on soap foams, Langmuir monolayer foams, metal grains, and simulations.

J Immunol Methods, 1999 Jan 1, 222(1-2), 135 - 44
High-level and effective production of human mannan-binding lectin (MBL) in Chinese hamster ovary (CHO) cells; Ohtani K et al.; We have developed a high-expression system of recombinant human mannan-binding lectin (MBL) with CHO cells . Geneticin-resistant transformants harboring human MBL cDNA in the expression vector pNOW/CMV-A were screened by immunoblot analysis for secretion of recombinant MBL . Cloning and selection by both geneticin and methotrexate resulted in the production of recombinant MBL to a final concentration of 128.8 microg/ml in media after four days of culture . SDS-PAGE and gel-filtration analyses showed that recombinant MBL is characterized by two lower-order oligomeric structures (apparent molecular weights: 1150 kDa and 300 kDa) compared to native MBL (apparent molecular weight: 1300 kDa) . The recombinant human MBL has both sugar-binding and complement activation activity and, like native MBL, can inhibit hemagglutination of influenza A virus . Lectin blots with recombinant MBL indicate that it can bind such microorganisms as HIV and influenza virus suggesting that it might inhibit their infection of hosts . This high-level expression of human MBL with the full range of biological activity will be useful for studies on the immunological role of MBL in humans.

Toxicol Lett, 1998 Dec 28, 102-103, 283 - 7
Immune and inflammatory responses in the CNS: modulation by astrocytes; Aschner M; Because the skull bones, the cerebrospinal fluid, the blood-brain barrier (BBB), and the meninges effectively shield the central nervous system from other tissues, it was proposed that the brain is an 'immunologically privileged' organ . However, with recent evidence that in response to invasion by microorganisms, resident cells, such as astrocytes and microglia can fully mount an immune response, this long-standing view has been rethought and revised . Over the last two decades, both astrocytes and microglia have been shown to secrete numerous cytokines, and, therefore, it is presently widely accepted that these cells actively participate in an integrative communicative pathway between resident immune cells of the CNS and those of the periphery . While clearly implicated in the initiation, maintenance, and suppression of immune responses, cytokines produced by these cells (e.g . astrocytes and microglia), as well as the responses of these cells to cytokines produced elsewhere, has also been shown to propagate CNS damage . Therefore the potential involvement of these cells in neurodegenerative disorders has been raised and subjected to intense experimentation . The objective of this synopsis is to review the role played by astrocytes in the initiation and modulation of immune responses.

J Exp Biol, 1999 Mar, 202 ( Pt 6), 645 - 53
Inducible NO synthase: role in cellular signalling; Beck KF et al.; The discovery of endothelium-derived relaxing factor and its identification as nitric oxide (NO) was one of the most exciting discoveries of biomedical research in the 1980s . Besides its potent vasodilatory effects, NO was found under certain circumstances to be responsible for the killing of microorganisms and tumour cells by activated macrophages and to act as a novel, unconventional type of neurotransmitter . In 1992, Science picked NO as the 'Molecule of the Year', and over the past years NO has become established as a universal intercellular messenger that acutely affects important signalling pathways and, on a more long-term scale, modulates gene expression in target cells . These actions will form the focus of the present review.

Diagn Microbiol Infect Dis, 1999 Jan, 33(1), 1 - 6
The detection of positive blood cultures by the AccuMed ESP-384 system: the clinical significance of three-day testing; Han XY et al.; A total of 805 positive blood cultures obtained over a 4-month period during 1997 by the AccuMed ESP-384 system were evaluated and compared with 471 positive blood cultures obtained during 1989 . Of the 805 microorganisms isolated in 5-day culture and testing by the ESP-384, 671 (83.4%) were detected within the first 2 days and 758 (94.2%) within 3 days . There were 47 (5.7%) microorganisms detected in culture Days 4 and 5 from 42 patients and review of the medical records from these patients demonstrated that no significant changes in clinical management were instituted as a result of detection and identification of these isolates . These 47 organisms were considered to be zero to equivocal clinical relevance . These data suggest that a 3-day routine blood culture incubation protocol with the ESP-384 system may be sufficient when considering detection rate, clinical relevance, and cost-effectiveness . The microbial spectrum and relative frequencies in this study were found to be similar to those of positive blood cultures obtained during 1989.

Klin Khir, 1998, (6), 23 - 6
{Risk factors determining the outcome of a diffuse peritonitis of appendicular genesis in children}; Moskalenko VZ et al.; The peculiarities of pre-, intra- and early postoperative period course in 108 children, operated on for diffuse and general peritonitis of appendicitis origin, are studied . Most significant 34 prognostic factors for the disease outcome are choosed . The leading factors are the disease course duration, general condition of the patient while hospitalization, the vegetative disorders presence, the intestinal paresis degree, the biochemical inductors of stress contents, the peritoneal exudate character, the kind and composition of microorganisms in it, the character of an early postoperative period course.

Mol Microbiol, 1998 Dec, 30(5), 1003 - 15
Identification of a 47 kDa fibronectin-binding protein expressed by Borrelia burgdorferi isolate B31; Probert WS et al.; The attachment of pathogenic microorganisms to host cells and tissues is often mediated through the expression of surface receptors recognizing components of the extracellular matrix (ECM) . Here, we investigate the ability of Borrelia spirochaetes to bind the ECM constituent, fibronectin . Borrelia lysates were separated by SDS-PAGE, transferred to nitrocellulose and probed with alkaline phosphatase-labelled fibronectin (fibronectin-AP) . Five of six Borrelia species and four of eight B . burgdorferi sensu lato isolates expressed one or more fibronectin-binding proteins . Borrelia burgdorferi isolate B31 expressed a 47 kDa (P47) fibronectin-binding protein that was localized to the outer envelope based on susceptibility to proteinase K . The interaction of P47 with fibronectin was specific, and the region of fibronectin bound by P47 mapped to the gelatin/collagen binding domain . P47 was purified by affinity chromatography, digested with endoproteinase Lys-C, and the peptide fragments analysed by liquid chromatography/tandem mass spectroscopy . A search of protein databases disclosed that the P47 peptide mass profile matched that predicted for the bbk32 gene product of B . burgdorferi isolate B31 . The bbk32 gene was cloned into Escherichia coli, and the ability of recombinant BBK32 to bind fibronectin and inhibit the attachment of B . burgdorferi was demonstrated . The identification of BBK32 as a receptor for fibronectin binding may enhance our understanding of the pathogenesis and chronic nature of Lyme disease.

J Biotechnol, 1999 Jan 8, 67(1), 1 - 11
Patenting in biotechnology: a review of the 20th symposium of ECB8; Szarka E; The patenting of biotechnological inventions is practically in harmony with the general requirements of patent protection . It stands still in the foreground of interests since this is the only technical field where the living material itself may be the subject matter of patents . In consequence ethical problems have arisen first of all in the patenting of human cells and genes in which there is no agreement between R&D firms, patent offices and green movements . This has called for the elaboration of special Directives . On the other hand, patent systems are instrumental in safeguarding biodiversity . This review gives a picture of the patenting situation in biotechnology in the European Patent Office and in Hungary, the host country of the Congress . It also gives practical advice to biotechnological researchers on how to draft the applications and to observe the time limits, as well as on the necessity and possibilities of the deposit of microorganisms.

J Clin Microbiol, 1999 Mar, 37(3), 600 - 5
Typing of clinical Mycobacterium avium complex strains cultured during a 2-year period in Denmark by using IS1245; Bauer J et al.; In the present study restriction fragment length polymorphism analyses with the recently described insertion sequence IS1245 as a probe was performed with clinical Mycobacterium avium complex strains cultured in Denmark during a 2-year period . The overall aim of the study was to disclose potential routes of transmission of these microorganisms . As a first step, the genetic diversity among isolates from AIDS patients and non-human immunodeficiency virus (HIV)-infected patients was described . In addition, a number of isolates from nonhuman sources cultured during the same period were analyzed and compared to the human isolates . A total of 203 isolates from AIDS patients (n = 90), non-HIV-infected patients (n = 91), and nonhuman sources (n = 22) were analyzed . The presence of IS1245 was restricted to Mycobacterium avium subsp . avium isolates . The majority of human isolates had large numbers of IS1245 copies, while nonhuman isolates could be divided into a high-copy-number group and a low-copy-number group . Groups of identical strains were found to be geographically widespread, comprising strains from AIDS patients as well as strains from non-HIV-infected patients . Samples of peat (to be used as potting soil) and veterinary samples were found to contain viable M . avium isolates belonging to genotypes also found in humans.

Cell Immunol, 1999 Feb 1, 191(2), 117 - 23
Mycobacterium avium complex activates nuclear factor kappaB via induction of inflammatory cytokines; Ghassemi M et al.; A variety of microorganisms has been reported to directly induce NF-kappaB, a critical step in the regulation of genes involved in the cellular immune response . In this study, we demonstrate that proinflammatory cytokines such as tumor necrosis factor alpha (TNFalpha) produced upon activation by the Mycobacterium avium complex (MAC) preceed NF-kappaB activity in U937, a human monocytoid cell line . MAC induction of TNFalpha mRNA expression was detected within 15 min after MAC infection, whereas enhanced NF-kappaB binding activity was not detected until 90 to 120 min postinfection . Supershift analysis revealed increased p50 in the MAC-induced NF-kappaB binding complexes . Consistent with an autocrine mechanism, anti-TNFalpha antibody and dexamethasone, a known cytokine inhibitor, both completely suppressed the effect of MAC on the induction of NF-kappaB . Taken together, these findings suggest that exposure of monocyte cell membranes to MAC induces endogenous TNFalpha, which in turn enhances NF-kappaB binding activity . The rapid induction of TNFalpha may be important in the initial host response to MAC infection .

J Immunol, 1999 Feb 1, 162(3), 1611 - 7
CpG oligodeoxynucleotides can circumvent the Th2 polarization of neonatal responses to vaccines but may fail to fully redirect Th2 responses established by neonatal priming; Kovarik J et al.; Neonatal murine responses to a panel of conventional vaccines differ qualitatively from adult responses by a particular polarization toward a Th2 pattern and a frequent limitation of the Th1 and CTL responses required for protection against intracellular microorganisms . In contrast, DNA vaccines induce adult-like Th1/CTL neonatal responses against the same vaccine Ags . In this report, we show that this can be related to their content in unmethylated CpG motifs . Oligodeoxynucleotides (ODN) containing CpG motifs activate neonatal APCs to produce IL-12 in vitro and induce adult-like Th1 responses to tetanus toxoid and measles Ags in vivo, with production of IgG2a-specific Abs and adult-like secretion of IFN-gamma and IL-5 by Ag-specific T cells . However, in spite of their capacity to trigger neonatal B cell proliferation in vitro, CpG-ODN only partially enhanced early life Ab responses . Finally, using Th1-driving CpG-ODN with the boosting dose of a protein vaccine was sufficient to redirect adult but not neonatally primed Th2 responses . These observations could be important for the development of novel vaccines that will have to be effective early in life.

J Immunol, 1999 Feb 1, 162(3), 1310 - 7
Comparison of lung dendritic cells and B cells in stimulating naive antigen-specific T cells; Masten BJ et al.; Dendritic cells (DCs) are specialized APCs that are important in priming naive T cells and can be manipulated in vitro and in vivo to enhance immunizations against microorganisms and tumors . A limitation in the development of suitable immunotherapeutic vaccines for the lung is incomplete information on the role of DCs and other potential APCs in the lung in priming naive T cells . In the current study, we analyzed the relative contributions of murine lung DCs and B cells to process and present OVA to naive CD4+ OVA323-339-specific (DO11.10) T cells in vitro . We also examined their expression of MHC class II and accessory molecules before and after maturation in culture . Similar to DCs from other sites, freshly isolated lung DCs can process OVA, spontaneously up-regulate MHC class II and accessory molecules during overnight culture, and stimulate naive T cells in an Ag-specific manner . In contrast, freshly isolated lung B cells were unable to both process and present native OVA . Furthermore, under conditions of limited OVA323-339 peptide exposure, B cells had a significantly diminished capacity to stimulate T cells, and this correlated with a decreased density of both MHC class II and important costimulatory molecules as compared with lung DCs.

FASEB J, 1999 Feb, 13(2), 305 - 12
A role for preadipocytes as macrophage-like cells; Cousin B et al.; Several lines of evidence have supported a link betweeen adipose tissue and immunocompetent cells . This link is illustrated in obesity, where excess adiposity and impaired immune function have been described in both humans and genetically obese rodents . In addition, numerous factors involved in inflammatory response are secreted by both preadipocytes and macrophages . Here we show that proliferating preadipocytes in cell lines and primary cultures, develop phagocytic activity toward microorganisms . This is demonstrated by phagocytosis assays and confocal microscopy . This function disappears when preadipocytes stop proliferating and differentiate into adipocytes . After phagocytosis, preadipocytes show microbicide activity via an oxygen-dependent mechanism . In addition, preadipocytes as well as adipocytes are stained with MOMA-2, a marker of monocyte-macrophage lineage, but are negative for specific mature macrophage markers (F4/80 and Mac-1) . These results suggest that preadipocytes could function as macrophage-like cells and raise the possibility of a potential direct involvement of adipose tissue in inflammatory processes.

Biosci Biotechnol Biochem, 1998 Nov, 62(11), 2257 - 9
Evidence that a beta-1,4-endoglucanase secreted by Acetobacter xylinum plays an essential role for the formation of cellulose fiber; Koo HM et al.; Cellulose-producing Acetobacter xylinum has been known to secrete a cellulose-hydrolyzing beta-1,4-endoglucanase (CMCax) . When antibodies to recombinant CMCax were added to the culture medium, the formation of cellulose fiber was severely inhibited . Western blot analysis using the antibody showed that this enzyme was secreted into the medium even by a cellulose non-producing strain (Cel-) . These results indicate that beta-1,4-endoglucanase in the medium plays a critical role in the formation of cellulose fiber by the microorganism.

Hepatogastroenterology, 1998 Nov-Dec, 45(24), 2270 - 4
Effect of tuftsin on human Kupffer cell; Kubo S et al.; BACKGROUND/AIMS: Kupffer cells are the most important category of reticuloendothelial cells which are critical for host defense in the liver . We investigated the effects of tuftsin (Thr-Lys-Pro-Arg) on human Kupffer cells . METHODOLOGY: Human Kupffer cells were obtained from the livers of patients with colon cancer . Phagocytosis assay was done by microscopic counting of the number of Kupffer cells that engulfed fluorescent particle(s), and the number of the particles engulfed per Kupffer cell when Kupffer cells were incubated with and without tuftsin . Effect of tuftsin on the release of tumor necrosis factor from Kupffer cells was also studied . RESULTS: Phagocytosis was enhanced significantly by tuftsin . The greatest effect on percentage of phagocytic cells was observed at 1.0 microg/ml of tuftsin . The mean number of particles engulfed per Kupffer cell was also increased with tuftsin 1.0 microg/ml . Tumor necrosis factor release was also significantly increased; the greatest effect was observed at 1.0 microg/ml of tuftsin . CONCLUSIONS: Tuftsin enhances phagocytic activity and tumor necrosis factor release of human Kupffer cells, which are advantageous for host defense against invading microorganisms and tumor cells.

Int J Lepr Other Mycobact Dis, 1998 Sep, 66(3), 365 - 73
Mycobacterium lepraemurium, a well-adapted parasite of macrophages: I . Oxygen metabolites; Rojas-Espinosa O et al.; We measured the release of reactive oxygen intermediaries {ROI (hydrogen peroxide and superoxide anion)} by murine peritoneal macrophages challenged in vitro with Mycobacterium lepraemurium (MLM), complement-opsonized yeast, M . bovis BCG, M . phlei, or phorbol myristate acetate (PMA) . We found that except for MLM, all of the other materials provoked the release of significant amounts of hydrogen peroxide and superoxide . MLM entered the macrophages without triggering their oxidative metabolism . Pre-infection of macrophages with MLM did not alter these cells' capacity to release the normal amounts of ROI in response to other microorganisms or PMA . Killing of MLM did not revert the macrophages' failure to release ROI upon ingestion of the microorganism, nor were macrophages able to produce these toxic metabolites when pre-incubated in the presence of murine gamma interferon (IFN-gamma) . MLM has several attributes that allow it to survive within macrophages: a) it is a nontoxigenic microorganism (it does not harm its host), b) it resists the harsh conditions of the intraphagolysosomal milieu (a property perhaps dependent on its thick lipidic envelope), and c) it penetrates the macrophages without triggering their oxidative response (thus avoiding the generation of the toxic intermediaries of oxygen) . For these attributes (and others discussed in this paper), we recognize MLM as a highly evolved, well-adapted parasite of macrophages . In addition, the results of the present study prompted the analysis of the biochemical pathways used by MLM and M . bovis BCG to penetrate into their cellular hosts, a subject now under investigation in our laboratory.

Adv Biochem Eng Biotechnol, 1999, 63, 169 - 218
Microbial models for drug metabolism; Azerad R; This review describes microbial transformation studies of drugs, comparing them with the corresponding metabolism in animal systems, and providing technical methods for developing microbial models . Emphasis is laid on the potential for selected microorganisms to mimic all patterns of mammalian biotransformations and to provide preparative methods for structural identification and toxicological and pharmacological studies of drug metabolites.

Adv Biochem Eng Biotechnol, 1999, 63, 57 - 72
Stereoinversions using microbial redox-reactions; Carnell AJ; This paper aims to provide a summary of the recent literature on the use of redox enzymes to carry out stereoinversion reactions on chiral secondary alcohols . Emphasis has been placed on biotransformations which result in the deracemization of a racemic substrate to give high value synthetic intermediates in a theoretical 100% yield . Most of the biocatalysts which are competent to carry out such transformations are whole cell systems, which contain the necessary cofactor recycling machinery to facilitate this otherwise entropically disfavoured process . The first section deals with deracemization of compounds such as mandelic acid and pantoyl lactone using two microorganisms which display enantiocomplementary stereospecificity . The deracemization of chiral alcohols such as beta-hydroxyesters, aryl ethanols and terminal 1,2-diols with single microorganisms will then be discussed and the influence of growth and reaction conditions on the selectivity observed will be emphasised . Then the ability of several microorganisms to deracemize by double stereoinversion substrates with two stereocentres such as cyclohexan-1,2-diol, cis and trans indan-1,2-diol and pentan-2,4-diol will be presented and some mechanistic rationale proposed . Lastly enzymes known as epimerases which are important in sugar and deoxysugar biosynthesis will be discussed with reference to some recent work on the mechanism of UDP-glucose epimerase.

FEMS Microbiol Lett, 1999 Jan 15, 170(2), 363 - 71
Bioaccumulation of heavy metals by fimbrial designer adhesins; Schembri MA et al.; Naturally occurring adhesins bind to specific molecular targets in a lock-and-key fashion due to the composition of the binding domain of the adhesin . By introduction of random peptide libraries in a suitable surface exposed carrier protein it is possible to create and select designer adhesins with novel binding affinities . Type 1 fimbriae are surface organelles of Escherichia coli which mediate D-mannose sensitive binding to different host surfaces through the FimH adhesin, an integral part of these organelles . We have studied the ability of the FimH adhesin to display random peptide sequences . By serial selection and enrichment procedures specific sequences were identified which conferred the ability on recombinant cells to adhere to various metal oxides (PbO2, CoO, MnO2, Cr2O3) . The properties inherent in these sequences permitted the distinct recognition of metals to varying degrees, indicating that this system allow for the isolation of peptide sequences with a variety of binding avidities . These studies demonstrate the potential and versatility of the FimH display system for presenting random peptide sequences . In addition, the possibility exists for the construction of microorganisms for the bioaccumulation of heavy metals from the environment.

Clin Exp Immunol, 1999 Feb, 115(2), 229 - 35
Regulation of CR3 (CD11b/CD18)-dependent natural killer (NK) cell cytotoxicity by tumour target cell MHC class I molecules; Vetvicka V et al.; Phagocyte and NK cell CR3 functions as both an adhesion molecule and an iC3b receptor mediating cytotoxic responses to microorganisms . Cytotoxic activation of iC3b receptor function requires ligation of both a CD11b I-domain site for iC3b and a lectin site located in the C-terminus of CD11b . Because tumours lack the CR3-binding polysaccharides of bacteria and fungi, iC3b-opsonized tumours do not stimulate CR3-dependent cytotoxicity . Previous studies showed that NK cells could be induced to kill iC3b-opsonized tumours with small soluble beta-glucans that bound with high affinity to CR3, bypassing the absence of similar polysaccharides on tumour membranes . Because CR3 signalling requires several tyrosine phosphorylation events, it appeared possible that CR3-dependent killing of autologous tumour cells might be suppressed by NK cell inhibitory receptors for MHC class I (KIR and CD94/NKG2) whose action involves recruitment of SHP-1 and SHP-2 tyrosine phosphatases . In the current study, Epstein-Barr virus (EBV)-transformed B cells were used as targets following opsonization with iC3b . Soluble beta-glucan primed CR3 for killing of iC3b-coated B cells, but autologous class I-bearing targets were 84% more resistant than class I-deficient Daudi cells . Blockade of target cell class I with a MoAb specific for a domain recognized by both KIR and CD94/NKG2 resulted in comparable killing of class I+ B cells . By contrast, another MoAb to class II had no effect on cytotoxicity . These data suggest that NK cell recognition of class I suppresses CR3/tyrosine kinase-dependent cytotoxicity in the same way as it suppresses cytotoxicity mediated by other tyrosine kinase-linked receptors such as FcgammaRIIIA (CD16).

Am J Ophthalmol, 1999 Jan, 127(1), 77 - 84
Disinfection of tonometers and contact lenses in the office setting: are current techniques adequate?
Smith CA, Pepose JS.
PURPOSE: To determine whether routine office techniques used to disinfect tonometer prisms and trial contact lenses are sufficient to prevent transmission of ocular infections . METHOD: We reviewed the current literature on the efficacy of certain disinfection protocols against commonly encountered viral, bacterial, and fungal pathogens as well as Acanthamoeba . RESULTS: Some commonly used disinfecting solutions and techniques may be inadequate for disinfection of viruses such as hepatitis C virus and organisms such as Acanthamoeba . When used in accordance with guidelines published by the United States Centers for Disease Control and Prevention (CDC) and the American Academy of Ophthalmology (AAO), 3% hydrogen peroxide is a very effective disinfectant against a wide variety of microorganisms . Specifically, tonometer prisms disinfected by a 5-minute soak in 3% hydrogen peroxide (or 70% isopropyl alcohol or a 1:10 dilution of sodium hypochlorite) are adequately disinfected against most ocular pathogens, with the exception of Acanthamoeba . Trial contact lenses that are disinfected with a 2-hour soak in 3% hydrogen peroxide are effectively rid of all pathogens of concern . After disinfection, rigid lenses should be stored dry, and soft lenses should be stored in a sterile, preserved solution . Repeat disinfection should be routinely performed at 1-month intervals to prevent regrowth of organisms . CONCLUSION: A safe office environment can be maintained by following current CDC recommendations for disinfection, as well as instituting some additional procedures.

Langenbecks Arch Chir Suppl Kongressbd, 1998, 115, 439 - 42
{Pathogenesis of pancreatogenic sepsis}; Runkel N; The intestinal tract is the motor of sepsis in the "gut-MOF hypothesis" . Acute pancreatitis causes an early severe reduction of intestinal microcirculation with consequent production of radicals and cytokines damaging intestinal integrity . The intestinal organ dysfunction syndrome results in a breakdown of barrier function and a loss of propulsive activity . This leads to microbial overgrowth and bacterial translocation . This liberates cytokines and causes secondary pancreatic infection after lymphatic and systemic bacterial dissemination . Infected pancreatic necrosis by enteric microorganisms is the main cause of pancreatic sepsis.

Gene, 1999 Jan 21, 226(2), 139 - 46
Multiple p450alk (cytochrome P450 alkane hydroxylase) genes from the halotolerant yeast Debaryomyces hansenii; Yadav JS et al.; The halotolerant alkane-assimilating yeast Debaryomyces hansenii was examined for P450 alkane hydroxylase genes known to be required for alkane assimilation in Candida . Four distinct P450alk gene segments and an allelic segment were isolated using PCR based on degenerate primers derived from the CYP52 family of alkane-inducible P450 genes . A screen of a genomic library (15-20kb inserts) constructed for this study, using a probe based on the PCR-isolated segments, yielded seven clones . This has led to the isolation and sequence of two full-length genes DH-ALK1 and DH-ALK2 . These genes, each with an ORF of 1557 bp (519 aa), contained no apparent introns and showed 64% nucleotide sequence homology (61% based on the deduced amino acid sequences) . The deduced proteins had predicted molecular weights of 59,254Da (DH-ALK1) and 59,614Da (DH-ALK2) and have been designated CYP52A12 and CYP52A13 by the P450 Nomenclature Committee . Phylogenetic analysis based on Neighbor Joining Tree showed that DH-ALK1 and DH-ALK2 constitute new genes located on two distinct branches and are most related to the gene CYP52A3 (60% deduced aa homology) and are least related to the gene CYP52C2 (41% deduced aa homology), both of C . maltosa . The isolated genes will provide tools to better understand the diversity of the P450alk family in eukaryotic microorganisms adapted to varied environmental conditions.

Rev Clin Esp, 1998 Dec, 198(12), 805 - 9
{Seroepidemiology of Bartonella henselae infection in a risk group}; Blanco Ramos JR et al.; BACKGROUND: Bartonella henselae infections are closely related to a number of clinical conditions of growing interest in our environment . As cats are the reservoir, and their bites and scratches are the main transmission mechanism, we attempted to study the seroepidemiology of the infection caused by this microorganism in a risk group of patients (cat owners) and a control group (blood donors) . PATIENTS AND METHODS: October 1977 . Measurement of antibody titres to B . henselae at different dilutions (breakpoint > or = 1:64) by indirect immunofluorescence (IFI) in 83 cat owners and 85 blood donors . Also, an epidemiologic investigation was carried out (age, sex, alcohol, intake, common cat exposure, cat bite or cat scratch, number and age of cats, bite or presence of fleas, use of repellents, clinical picture consistent with cat scratch disease {CSD}) . RESULTS: Twenty-four cat owners (28.9%) and five blood donors (5.9%) had titres > or = 1:64 (OR: 6.51; 95% CI: 2.32 to 22.9) . Also, the logistic regression analysis showed an association with daily alcohol intake and the previous antecedent of lymph node enlargement of unknown origin among cat owners . CONCLUSIONS: A high prevalence of antibodies to B . henselae was demonstrate among cat owners.

Rev Clin Esp, 1998 Dec, 198(12), 789 - 93
{Preliminary report of an epidemic tularemia outbreak in Valladolid}; Bachiller Luque P et al.; We make here a preliminary report of the first 65 cases of tularemia diagnosed at our hospital pertaining to an epidemic outbreak occurred in the area served by the hospital . Diagnosis was made by the presence of a consistent clinical picture and the following laboratory criteria: antibody titre to . Francisella tularensis (tube agglutination) higher than or equal to 1/160, seroconversion or recovery of the microorganism from biological material . The mean age of our patients was 53.8 +/- 13.5 years and female sex predominated (45 women) . Fever, lymph node enlargement, cutaneous ulcers, asthenia, and weight loss were the most common symptoms . The presentation clinical forms included: ulceroganglionar (69%), typhoidal (14%), ganglionar (12.5%), pneumonic (1.5%), oculoganglionar (1.5%) and atypical (1.5%) . The analytical data did not show significant changes with the exception of erythrocyte sedimentation rate . Streptomycin was the antibiotic of choice, followed by ciprofloxacin and gentamicin . The failure rate was 22%, and ciprofloxacin was used for retreatment in twelve occasions and ofloxacin in 1 occasion with a good response . Tularemia is an infective disease which can become endemic in Spain and that should be considered by clinicians, particularly when unilateral enlarged lymph nodes, prolonged febrile syndromes, pharyngitis with negative culture, poor response to beta-lactams and atypical pneumonia are present.

Baillieres Clin Rheumatol, 1998 Nov, 12(4), 649 - 64
The spectrum of skin, mucosa and other extra-articular manifestations; Angulo J et al.; The seronegative spondyloarthropathies appear to be the genetically predisposed host's clinical expression to acute, subacute or chronic reaction to the invasion by environmental microorganisms . In the ensuing days or weeks, depending on the infectious load, clinical manifestations may occur ranging from constitutional complaints such as fever, to a variety of symptoms and/or signs related to the portal of entry-intestinal, genitourinary or respiratory . Within weeks or months, the initial or other target organs, such as the mucocutaneous, ocular and cardiovascular systems, may develop an acute reaction of greater or lesser specificity regarding the triggering agent (oral ulcers, circinate balanitis, erythema nodosum, acute anterior uveitis, pericarditis, heart blocks) . Lastly, many years later, a minority of patients, probably those with a large genetic component, exhibit a spectrum of clinical manifestations related to those organs, with a chronic or recurrent course . Acute clinical manifestations--reactive arthritis--are prominent in the initial phase of the clinical spectrum, while chronic manifestations--ankylosing spondylitis--are seen at the other end of the spectrum.

Ann N Y Acad Sci, 1998 Nov 17, 859, 65 - 74
Interaction of microorganisms, epithelium, and lymphoid cells of the mucosa-associated lymphoid tissue; Hamzaoui N et al.; Differentiation of specific epithelial cell lineages during development, as well as epithelial plasticity in response to heterologous cell-to-cell cross talk during adult life, accounts for the large variety of functions which are performed by the mucosal surfaces found in the human body . Among its functions, the digestive mucosa is able to sample antigens and microorganisms through M cells of Peyer's patches' follicle-associated epithelium, in order to trigger the development of either tolerance or immune responses . At least in the gut, M-cell formation is immunoregulated . Close contact between immune cells and intestinal epithelium modifies the permeability of the epithelial barrier by inducing the conversion of enterocytes into M cells, offering at the same time an opportunistic way of invasion for pathogens . These lympho-epithelial interactions triggering M-cell formation have now been modeled in culture.

Ann N Y Acad Sci, 1998 Nov 17, 859, 37 - 45
Interactions between epithelial cells and immune cells in the intestine; Strober W; Not merely a passive barrier as previously assumed, epithelial cells act as sensitive indicators of infection that initiate defense responses . Noninvasive as well as invasive organisms have been demonstrated to elicit production of chemoattractants . That noninvasive organisms have this capacity suggests that receptor-mediated signaling pathways may be involved . Epithelial cells have been found to release both chemokines and cytokines in a precise mixture that varies according to the origin or maturity of the cell . Different microorganisms also elicit different response patterns . The information presented provides a basis for a new view of epithelial cell function in relation to host defense.

Gastroenterol Hepatol, 1998 Dec, 21(10), 479 - 82
{Incidence and clinical features of splenic abscesses, with special reference to tuberculous etiology in a general hospital}; Arruabarrena I et al.; BACKGROUND: The aim of this revision is to know the incidence of splenic abscess (SA) in our hospital, its etiology, with special reference to tuberculosis, and clinical characteristics . PATIENTS AND METHODS: Abdominal CT-scan performed during the period 1987-1997, with the diagnosis of splenic abscess were reviewed . Etiologic diagnosis standed on blood or sputum cultures, PAAF and/or histologic study of lymph nodes . RESULTS: Seventeen cases of SA were obtained, 12 males and 5 females . Limits of age: 13 and 77 years . The causal microorganisms were: M . tuberculosis (7), Mycobacterium aviumintracellulare (1), S . aureus (2), S . anginosus (1), S . milleri (1), E . coli (1), C . albicans (1), T . biguelle (1) and polymicrobian flora (1) . One case was of unknown etiology . Underlying illnesses were: AIDS (7), malignant neoplasms (3), diabetes (2), endocarditis (2), Sjogren syndrome (1) and complications of abdominal surgery (2) . Clinical presentation in nontuberculous splenic abscess was fever and upper-left abdominal pain . Predominant symptoms in tuberculous splenic abscess were fever and weight loss . Blood cultures were positive in 80% of non tuberculous splenic abscess . Specific treatment for tuberculosis improved all patients with tuberculous splenic abscess, without needing surgery or corticosteroids . CONCLUSIONS: From the total of splenic abscess, 41.1% were tuberculous, six with AIDS and one with Sjogren syndrome . Diabetes and malignant neoplasms were the commonest underlying illnesses in the non-tuberculous . In these, clinical presentation consisted in fever and upper-left abdominal pain . In patients with tuberculous splenic abscess, the main complaint was weight loss . A prompt treatment is generally succesful.

Insect Mol Biol, 1999 Feb, 8(1), 125 - 32
Tissue tropism, transmission and expression of foreign genes in vivo in midgut symbionts of tsetse flies; Cheng Q et al.; Tsetse flies (Diptera: Glossinidae) harbour three different symbiotic organisms in addition to the pathogenic African trypanosomes they transmit . The two gut-associated symbionts (primary, P; secondary, S) are enteric and are nutritionally required, whereas the third microorganism Wolbachia (family Rickettsiaceae) affects the reproductive biology of the insects it infects . The bacteriome-associated P-symbiont (Wigglesworthia glossinidia) displays a concordant phylogeny with its host tsetse species, whereas midgut S-symbionts characterized from distant tsetse have identical 16S rDNA sequences and therefore may either represent recent independent acquisitions or horizontal transfer between species . The S-symbionts have been cultured in vitro and a genetic transformation system has been developed . Here we report on their density and tissue tropism in different species (G . m . morsitans, G . p . palpalis, G . austeni and G . brevipalpis) and on their maternal route of transmission to tsetse progeny . Using a bacterium-specific PCR-assay, the S-symbionts were found primarily in the midgut, haemolymph, milk gland and in G . palpalis also in salivary glands of teneral flies . In older flies these infections were found to spread to other tissues including muscle, testes and fat body . The S-symbionts were transformed to express the marker gene product, Green Fluorescent Protein (GFP) in vitro . When the recombinant symbionts were introduced into the haemoceal of fertile female flies via intrathoracic microinjection, they were detected in the intrauterine progeny, indicating that haemolymph may provide a possible route for their transmission . The implications of these results for symbiont-host interactions and for transgenic strategies in tsetse are discussed.

Appl Environ Microbiol, 1999 Feb, 65(2), 422 - 30
Quantifying microbial diversity: morphotypes, 16S rRNA genes, and carotenoids of oxygenic phototrophs in microbial mats; N bel U et al.; We quantified the diversity of oxygenic phototrophic microorganisms present in eight hypersaline microbial mats on the basis of three cultivation-independent approaches . Morphological diversity was studied by microscopy . The diversity of carotenoids was examined by extraction from mat samples and high-pressure liquid chromatography analysis . The diversity of 16S rRNA genes from oxygenic phototrophic microorganisms was investigated by extraction of total DNA from mat samples, amplification of 16S rRNA gene segments from cyanobacteria and plastids of eukaryotic algae by phylum-specific PCR, and sequence-dependent separation of amplification products by denaturing-gradient gel electrophoresis . A numerical approach was introduced to correct for crowding the results of chromatographic and electrophoretic analyses . Diversity estimates typically varied up to twofold among mats . The congruence of richness estimates and Shannon-Weaver indices based on numbers and proportional abundances of unique morphotypes, 16S rRNA genes, and carotenoids unveiled the underlying diversity of oxygenic phototrophic microorganisms in the eight mat communities studied.

Appl Environ Microbiol, 1999 Feb, 65(2), 746 - 51
Isolation of a bacterial strain able to degrade branched nonylphenol; Tanghe T et al.; Conventional enrichment of microorganisms on branched nonylphenol (NP) as only carbon and energy source yielded mixed cultures able to grow on the organic compound . However, plating yielded no single colonies capable, alone or in combination with other isolates, of degrading the NP in liquid culture . Therefore, a special approach was used, referred to as "serial dilution-plate resuspension," to reduce culture complexity . In this way, one isolate, TTNP3, tentatively identified as a Sphingomonas sp., was found to be able to grow on NP in liquid culture . Remarkably, this isolate was able to be filtered through a 0.45-micrometer-pore-diameter filter . Moreover, isolate TTNP3 did not form visible colonies on mineral medium with NP, and it formed visible colonies on R2A agar only after a prolonged incubation of 1 week . High-performance liquid chromatography and gas chromatography-mass spectroscopy analysis of the culture media indicated that the strain starts the degradation of NP with a fission of the phenol ring and preferably uses the para isomer of NP and not the ortho isomer . No distinct accumulation of an intermediary product could be observed.

Pathologica, 1998 Oct, 90(5), 463 - 6
Inflammatory pseudotumor of the liver . Report of two cases; Yavuz E et al.; Inflammatory pseudotumor (IPT) is a rare lesion of the liver . We report two cases of IPT of the liver . Patients were a 32-year-old man and a 45-year-old female . Preoperative clinical diagnoses were respectively amebic abscess and metastatic tumor . Fine needle aspirations were performed and cytopathologic findings were compatible with an inflammatory process in both cases . Simple excision was performed in the first case and left lobectomy in the second one . Gross examination revealed expansive solid tumoral masses which measured 3 x 2 x 2 cm and 7 x 5 x 5 cm, respectively . Both lesions were yellow and firm . On microscopic examination, lesions were composed of fascicles of plump spindle cells intermingled with a varying number of plasma cells, lymphocytes and histiocytes . The spindle cell fascicles also contained a moderate amount of intercellular collagen . No microorganism was found on PAS, Giemsa, Grocott and Ziehl Nielsen stained sections . Plasma cells were immunoreactive for both kappa and lambda light chains, revealing their polyclonal nature . Since hepatocellular carcinoma is concerned in differential diagnosis, IPT is of particular clinical importance . Despite the limited experience with fine needle aspiration cytology, histopathologic diagnosis of IPT does not pose great difficulty.

J Endod, 1998 Sep, 24(9), 604 - 6
In vitro evaluation of the cytotoxicity and genotoxicity of root canal medicines on human pulp fibroblasts; Chang YC et al.; An intracanal medicine is often required because microorganisms in the dentinal tubes may be difficult to eliminate completely by instrumentation . Phenolic compounds are widely used in dental treatment as sedatives for the dental pulp or as disinfectants for caries and the root canal . In this study, propidium iodide fluorescence and DNA precipitation assay were used to investigated the cytotoxic and genotoxic effects of camphorated phenol and camphorated parachlorophenol on cultured human pulp fibroblasts in vitro . Both medicines reduced the content of double-stranded polynucleic acid of fibroblasts over a 24-h culture period in a concentration-dependent manner . Camphorated parachlorophenol was more cytotoxic than camphorated phenol . But, both medicines did not cause genotoxicity on pulp cells . The advantage of these experimental methods are simplicity and rapidity . Furthermore, this experimental system may be useful for preliminary cytotoxicity and genotoxicity screening of various dental medicines in vitro.

Rev Hosp Clin Fac Med Sao Paulo, 1998 Jul-Aug, 53(4), 202 - 4
{Reiter's syndrome and human immunodeficiency virus infection}; de Mello e Silva AC et al.; The increase of rheumatic disorders in HIV infected has been known for the last decade with special emphasis on Reiter's Syndrome . In spite of common sources of HIV and other microorganisms being important in the pathogenesis of Reiter's Syndrome, severe immunodeficiency may be important in the development of rheumatic diseases, mainly because of the presence of arthritogenic microorganisms . The decrease of TCD4 lymphocytes, the increase of TCD8 lymphocytes and the modification of immune regulation may be important in the pathogenesis of Reiter's Syndrome in patients infected by HIV . There is no clinical response to nonhormonal anti-inflammatory drugs in the treatment of this entity.

J Prosthet Dent, 1999 Feb, 81(2), 202 - 6
Disinfection of denture base acrylic resin; Lin JJ et al.; STATEMENT OF PROBLEM: During repair or adjustments of acrylic resin removable complete and partial dentures, particles of the acrylic resin from the interior of the prosthesis may expose dental personnel to microbial health hazards if the prosthesis has not been thoroughly disinfected . PURPOSE: This study investigates the efficacy of a commercially prepared microbial disinfectant (Alcide) on the external and internal surfaces of acrylic resins . MATERIAL AND METHODS: Four groups of acrylic resin were incubated in an experimental model to simulate the oral environment over time . Specimens were treated in 2 groups, disinfected and not disinfected, and then further grouped by breaking and not breaking . Analysis was performed with microbial colony counts, SEM, and statistical analyses . RESULTS: Viable microorganisms still remain on the internal and external surfaces of treated resins . CONCLUSION: Chlorine dioxide reduces, but does not eliminate, viable microorganisms on these dental prostheses.

Nurs Clin North Am, 1999 Mar, 34(1), 95 - 112
State of the art: antiretroviral and prophylactic treatments in HIV/AIDS; Porche DJ; HIV results in a continual and progressive pathological attack on the human immune system . This attack on the immune system can be altered with combination antiretroviral agents that interrupt the HIV life-cycle . There are three classes of approved antiretroviral agents: nucleoside reverse transcriptase inhibitors, nonnucleoside reverse transcriptase inhibitors, and protease inhibitors . The progressive deterioration of the patient's immune system by HIV infection increases the likelihood of developing opportunistic infections . Primary measures that can be taken to prevent the development of opportunistic infections are preventing exposure to the microorganisms in the environment and maintaining a competent immune system using antiretroviral therapy through prophylactic agents specific to opportunistic infections.

Langenbecks Arch Surg, 1998 Dec, 383(6), 437 - 41
A new method to prevent wound infection: a controlled clinical trial in patients with combined liver and bile duct resection; Hiramatsu K et al.; INTRODUCTION: Despite advances in antibiotic prophylaxis, postoperative wound infection remains a major source of morbidity after digestive surgery . Its prevention is a challenging problem, especially in high-risk patients . The authors introduced a new method to prevent surgical wound infections and evaluated its efficacy in a prospective, randomized trial in markedly high-risk patients . METHODS: Patients with biliary tract carcinoma who were scheduled to undergo combined liver and extrahepatic bile duct resection with biliary reconstruction were randomly assigned to one of two groups, well matched in terms of clinical characteristics at baseline . In one group the new treatment was employed (sealed group, n=31), and in the other the wound was treated in the usual fashion (open group, n=28) . In the sealed group, povidone-iodine gel was administered to the subcutaneous tissue, and the skin and peritoneum were approximated with a continuous suture . Wound infection was registered up to 30 days after surgery . RESULTS: Wound infection occurred in 18 patients: 5 (16%) patients in the sealed group and 13 (46%) in the open group (P<0.05) . All 18 underwent preoperative percutaneous transhepatic biliary drainage and had positive bile culture findings . In 13 of these 18 patients (72%) the microorganisms isolated from the infected wound were identical to those in the bile . CONCLUSIONS: Our results confirm the close association between infected bile and wound infection in hepatobiliary surgery . Our new method, "direct wound sealing," is simple, easy to perform, virtually cost-free, and has the potential to prevent wound infections even in markedly high-risk patients.

J Biol Chem, 1999 Feb 5, 274(6), 3580 - 9
Molecular determinants of oligomer formation and complement fixation in mannose-binding proteins; Wallis R et al.; Rat serum mannose-binding protein (MBP-A) functions as part of the innate immune system by targetting complement toward potentially pathogenic microorganisms . In order to examine the molecular basis for complement activation, rat MBP-A has been overproduced in Chinese hamster ovary cells . Recombinant protein is post-translationally modified in the same way as the native lectin . Hydrodynamic studies indicate that MBP-A consists predominantly of covalent oligomers containing one to four copies of a subunit that comprises a trimer of polypeptides . These oligomers are non-interconverting and do not assemble into higher order structures at concentrations in excess of those normally found in serum . Disulfide bonds formed between cysteine residues at the N-terminal end of the collagen-like domain link polypeptides to form covalent oligomers . Analysis of wild-type MBP-A and MBP-A containing the substitution Cys6 --> Ser suggests that polypeptides within each trimeric structural unit are mostly linked by disulfide bonds between cysteine residues at positions 13 and 18 arranged in an asymmetrical configuration . Disulfide bonds involving Cys6 connect polypeptides within separate trimers . Analysis of chimeras between MBP-A and rat liver MBP (MBP-C) indicates that residues within the N-terminal region of the collagenous domain and the cysteine-rich domain of MBP-A enable assembly of trimers into higher order oligomers . The activity of MBP-A in a hemolytic complement fixation assay using mannan-coated sheep erythrocytes was approximately 20-fold greater than the activity of MBP-C . Analysis of the MBP chimeras and isolated oligomers of MBP-A reveals that the larger oligomers are more efficient at complement activation . These data indicate that the overall complement fixing activity of MBP-A is a function of the individual molecular activities of oligomers and their relative abundance within the serum.

FEMS Microbiol Lett, 1999 Jan 1, 170(1), 271 - 9
Changes in the microbial community in Japan Trench sediment from a depth of 6292 m during cultivation without decompression; Yanagibayashi M et al.; A sample of deep-sea sediment was obtained from the Japan Trench at a depth of 6292 m using a pressure-retaining sediment sampler . Microorganisms in the sediment sample were cultivated in marine broth 2216 at ambient pressure (65 MPa) without decompression, and at atmospheric pressure (0.1 MPa) as a control experiment . 16S ribosomal RNA genes (rDNA) were amplified by PCR from DNA extracted from the original sediment sample and the mixed cultures, and the nucleotide sequences were determined . The results of phylogenetic analysis based on 16S rDNA sequences indicated that microbial diversity in the original sediment samples showed a wide distribution of types in the domain Bacteria . Furthermore, in the mixed cultures incubated at 65 MPa without decompression, bacterial strains belonging to the Shewanella barophiles branch and the genus Moritella existed together at the beginning of cultivation, and Moritella strains became dominant towards the end of the cultivation period . Finally, in the mixed cultures incubated at atmospheric pressure, strains belonging to the genus Pseudomonas were dominant at all times . Analysis of fatty acids extracted from the cultures supported the phylogenetic results.

J Antibiot (Tokyo), 1998 Nov, 51(11), 973 - 82
Bioprobes for investigating mammalian cell cycle control; Osada H; Bioprobes are low molecular weight compounds which are useful for investigating mammalian cell functions . The use of bioprobes has substantially assisted the investigation of complex biochemical processes of the mammalian cell cycle . In this review, cell cycle inhibitors mainly isolated from the microorganism are described and their possibility as an antitumor agents is considered . Most cancer cells have some abnormality in the control mechanism of cell cycle progression . Cyclin-dependent kinases (Cdk), which are activated by the binding with the cyclin and simultaneously by the phosphorylation/dephosphorylation of itself, play important roles as engines in the cell cycle . Tubulins are considered to be one of the most important proteins of the cell division machinery . Therefore, Cdk inhibitors and tubulin binders are possible anticancer drugs . Since the function of proteins controlling the cell cycle is also regulated by phosphorylation and dephosphorylation, inhibitors of protein kinases and phosphatases are considered as possible an antitumor agents . We expect that some bioprobes will be developed for clinical use.

Pharmacotherapy, 1999 Jan, 19(1), 70 - 5
Cyclospora: review of an emerging parasite; Brown GH et al.; Cyclospora is a parasite traditionally associated with diarrhea in travelers to endemic countries . Recently, several cases of cyclosporiasis were reported in nontravelers in the United States and Canada, implicating various fruits and vegetables as vehicles of infection . The life cycle of cyclospora is not fully known, but is believed to involve both asexual and sexual stages of proliferation . Food- and water-borne transmission of infection have been implicated . Patients infected with Cyclospora cayetanensis have protracted watery diarrhea . Various generalized symptoms are also present, making cyclosporiasis indistinguishable from infectious diarrhea caused by other microorganisms . Diagnosis depends on identifying the organism by microbiologic examination of stool samples . Treatment consists of supportive care, maintenance of fluid and electrolyte status, symptomatic relief, and antibiotic therapy . Trimethoprim-sulfamethoxazole is the only antibiotic available that is effective in eradicating the organism.

Infect Immun, 1999 Feb, 67(2), 805 - 9
Intranasal immunization confers protection against murine Pneumocystis carinii lung infection; Pascale JM et al.; To evaluate the feasibility of mucosal immunization against Pneumocystis carinii (Pc) experimental infection, female BALB/c mice were intranasally immunized three times with soluble Pc antigens plus cholera toxin fraction B (Pc-CTB); control groups received either Pc antigen, CTB, or phosphate-buffered saline (PBS) alone . Two weeks after the last immunization, five animals from each group were sacrificed, and cellular and humoral immune responses were evaluated . The remaining five mice were CD4 depleted using a monoclonal antibody against mouse CD4 and inoculated with viable Pc . Significantly higher specific lymphoproliferative responses from tracheobronchial lymph node cells, immunoglobulin M (IgM) and IgG antibody levels in serum, and bronchoalveolar lavage (BAL)-derived IgA antibody concentrations were observed in the Pc-CTB group of mice relative to control groups (P < 0.01) . Five weeks after challenge, no Pc organisms were observed in the lung smears of the Pc-CTB group, while the animals receiving antigen, adjuvant, or PBS had progressively higher numbers of Pc microorganisms . By Western blot analysis, a strongly reactive 55- to 60-kDa antigen was recognized by BAL IgA and by serum IgG . In summary, mucosal immunization elicited specific cellular and humoral immune responses and protected against Pc lung infection after immunosuppression.

Infect Immun, 1999 Feb, 67(2), 469 - 77
The mannose receptor mediates uptake of pathogenic and nonpathogenic mycobacteria and bypasses bactericidal responses in human macrophages; Astarie-Dequeker C et al.; The mannose receptor (MR) is involved in the phagocytosis of pathogenic microorganisms . Here we investigated its role in the bactericidal functions of human monocyte-derived macrophages (MDMs), using (i) trimannoside-bovine serum albumin (BSA)-coated latex beads and zymosan as particulate ligands of the MR, and (ii) mannan and mannose-BSA as soluble ligands . We show that phagocytosis of mannosylated latex beads did not elicit the production of O2- . Zymosan, which is composed of alpha-mannan and beta-glucan, was internalized by the MR and a beta-glucan receptor, but the production of O2- was triggered only by phagocytosis through the beta-glucan receptor . Activation and translocation of Hck, a Src family tyrosine kinase located on lysosomes, has previously been used as a marker of fusion between lysosomes and phagosomes in human neutrophils . In MDMs, Hck was activated and recruited to phagosomes containing zymosan later than LAMP-1 and CD63 . Phagosomes containing mannosylated latex beads fused with LAMP-1 and CD63 vesicles but not with the Hck compartment, and the kinase was not activated . We also demonstrate that the MR was unable to distinguish between nonpathogenic and pathogenic mycobacteria, as they were internalized at similar rates by this receptor, indicating that this route of entry cannot be considered as a differential determinant of the intracellular fate of mycobacteria . In conclusion, MR-dependent phagocytosis is coupled neither to the activation of NADPH oxidase nor to the maturation of phagosomes until fusion with the Hck compartment and therefore constitutes a safe portal of entry for microorganisms.

Immunol Rev, 1998 Dec, 166, 377 - 84
Ichthyophthirius multifiliis: a model of cutaneous infection and immunity in fishes; Dickerson H et al.; The parasitic ciliate Ichthyophthirius multifiliis offers a useful system for the study of cutaneous immunity against an infectious microorganism . Naive fish usually die following infection, but animals surviving sublethal parasite exposure become resistant to subsequent challenge . This resistance correlates with the presence of humoral antibodies in the sera and cutaneous mucus of immune fish . A mechanism of immunity has recently been elucidated that involves antibody binding to surface proteins (referred to as immobilization antigens or i-antigens) located on the parasite cell and ciliary membranes . Antibody-mediated cross-linking of i-antigens triggers a response by the parasite resulting in its exit from the host . These effects can be observed directly on the surface of live fish . In addition to allowing the observation of effector responses in vivo, Ichthyophthirius also provides a means to study the ontogeny of the mucosal immune response . The sites of antigen capture and presentation, and the sites of antibody production, are unknown with regard to cutaneous immunity . Because the external epithelial surfaces of fish are often the points of pathogen entry, a basic understanding of the inductive immune mechanisms and immune cell interactions in the skin and gills is extremely important with regard to vaccine development . The development of Ichthyophthirius as an experimental system and how it might be used to address these issues are discussed in this review.

J Egypt Soc Parasitol, 1998 Dec, 28(3), 729 - 38
Detection of Microsporidia by different staining techniques; Awadalla HN et al.; Previous detection of Microsporidia relied mainly on electron microscopy and histopathology . Recently, non invasive methods were able to recognize this microorganism . In the present study, different stains were used as a means of diagnosing spores of Microsporidia in stool samples of immunosuppressed patients . The original modified trichrome stain (MTS) was used as a standard screening technique for all stool samples . Positive samples for Microsporidia were then stained with the trichrome blue stain, Didier's trichrome blue stain, acid-fast trichrome stain (AFT), modified Ziehl-Neelsen stain, giemsa stain and calcofluor white M2R stain . Both calcofluor and the AFT stains were most efficient . They could simultaneously detect coccidial oocysts and microsporidial spores . This is beneficial and time-saving in the diagnosis of stool samples of immunosuppressed patients, which usually contain more than one opportunistic protozoon . Both stains are easy to perform and require the least amount of staining and examination.

Free Radic Biol Med, 1999 Feb, 26(3-4), 482 - 90
Phagocytic killing of microorganisms by radical processes: consequences of the reaction of hydroxyl radicals with chloride yielding chlorine atoms; Saran M et al.; Chloride anions and hydrogen peroxide serve as substrates for myeloperoxidase (MPO) in order to produce hypochlorous acid (HOCl) as one of the major killing agents of phagocytic leukocytes . Apart from this role of being a substrate for the MPO-reaction the chloride anion has been considered as unreactive and has not been implicated in radical reactions which contribute to the killing process . From the inherent reactivities of the pertinent radicals (as determined by pulse radiolysis experiments), the great abundance of chloride, and the most probable distribution of reactants within the phagosome, we deduce estimates for the average life-time and free diffusion path-length in this milieu and arrive at a model according to which chloride ions enter into radical chains and influence the killing of ingested bacteria to an extraordinarily high extent . We propose that hydroxyl radicals--despite some controversial arguments in the literature--may still be considered as important contributors to cell killing especially since we show that their reactions are made more effective by producing chlorine radicals in a cyclic process . We furthermore present arguments how the phagocyte may protect itself from harmful actions of HOCl and H2O2 after the superoxide-generating activity of NADPH oxidase is turned off.

Curr Opin Rheumatol, 1999 Jan, 11(1), 24 - 33
The role of superantigens in vasculitis; Tervaert JW et al.; Multiple risk factors are involved in susceptibility to vasculitis . Inherited determinants may increase the risk but are insufficient to induce the disease . Environmental factors, such as infections, are important modulators and probably trigger the disease in most cases . One of the possible triggers may be a bacterial superantigen (SAg) . SAgs may activate autoreactive T cells that mediate autoimmune vessel wall destruction . Furthermore, SAgs may activate autoreactive B cells to produce autoantibodies that are involved in the pathophysiology of vasculitis, such as antineutrophil cytoplasmic autoantibodies or anti-endothelial cell antibodies . In patients with Kawasaki disease, Wegener's granulomatosis, and infection-related forms of vasculitis, SAg-producing microorganisms have regularly been found . Activation of circulating T cells and skewing of the T-cell repertoire have been reported in most forms of vasculitis . In the past year, for the first time, patients were described in which T-cell receptor V beta expansions were documented simultaneously with the typing of the microbial SAgs, providing evidence that the observed changes in the T-cell repertoire could be caused by these bacterial SAgs . In the future, elucidation of the immunologic mechanisms by which SAgs may play a role in the pathophysiology of vasculitis will provide more effective methods for the treatment of vasculitis.

Biochimie, 1998 Nov, 80(11), 911 - 21
Genomic organization analysis of acidophilic chemolithotrophic bacteria using pulsed field gel electrophoretic techniques; Amils R et al.; The genomic organization of acidophilic chemolithotrophic bacteria belonging to the genus Thiobacillus, Thiomonas and Leptospirillum was studied using pulsed field gel electrophoresis techniques (PFGE) . The electrophoretic analysis of intact DNA prepared from different strains showed that all have a circular chromosome, with sizes ranging from 1.9 Mb for Leptospirillum ferrooxidans ATCC 49879, the smallest genome for an acidophilic strict chemolithoautotrophic microorganism, to 3.8 Mb for Thiomonas cuprina DSM 5495, the largest in this study . The number of extrachromosomal elements present varied from none, as observed in several isolates of Leptospirillum ferrooxidan, to five in Thiobacillus thiooxidans ATCC 8085 . The mixotroph Thiomonas cuprina DSM 5495 was found to have a linear 50 kb megaplasmid which was inducible when the bacteria was grown in chemolithotrophic conditions . Low-frequency restriction fragment analysis (LFRFA) of different acidophilic chemolithotrophs and related species was carried out by PFGE to determine macrorestriction patterns for rare cutters (SpeI, XbaI, SwaI, PmeI), which were then used for taxonomic identification (karyotyping), genome size determination, and generation of physical and genetic maps.

Eur J Med Res, 1999 Jan 26, 4(1), 1 - 7
Ankylosing spondylitis and genitourinary infection; Lange U et al.; One hundred and thirty-four male and 32 female patients with ankylosing spondylitis and 33 women with pure ileitis terminalis Crohn were examined . The study protocol included a medical-rheumatological examination and thorough investigation for genitourinary infection . Urethroadnexitis was found in 37/134 male patients (2 patients suffered from balanitis, 17 patients from urethritis, 18 patients from prostatitis, and 2 patients from epididymitis), 15/32 female patients (11 of them had urethritis and in 4 cases urethritis associated with vaginitis) and 5/33 women with ileitis terminalis (every case with urethritis) . The microorganism isolated most frequently from patients with genitourinary infection was Chlamydia trachomatis . The majority of patients with genitourinary infection were HLA-B27 positive . Nevertheless, the following conclusions can be reached: (1) evidence of Chlamydia trachomatis infection is frequent in male and female patients with ankylosing spondylitis, (2) patients with genitourinary infection tend to have HLA-B27, and (3) furthermore, presence of genitourinary infection was not significantly associated with chronic illness.

Ann Allergy Asthma Immunol, 1998 Dec, 81(6), 585 - 92
Serum IgG antibodies against Wallemia sebi and Fusarium species in Finnish farmers; Lappalainen S et al.; BACKGROUND: Wallemia sebi and Fusarium species are common fungi in agricultural environments . Because Fusarium species are difficult to culture, and W . sebi has only recently been found in an agricultural environment with the use of a new culture medium, immunochemical methods may be important for evaluating exposure to these fungi . OBJECTIVE: Immunoglobulin (Ig) G antibodies against W . sebi and two Fusarium species were measured in the sera of Finnish farmers to estimate exposure to fungi . METHODS: Serum-specific IgG antibody levels against the fungi were determined in farmers with farmer's lung disease and asthma, as well as in asymptomatic farmers with low and high IgG antibody levels against other agricultural microorganisms, and in control persons (printing and office workers) . Both enzyme-linked immunosorbent assay (ELISA) and enzyme-linked immunofiltration assay (ELIFA) techniques were used . RESULTS: Significantly higher IgG antibody levels against the fungi studied were observed in farmer's lung patients and asymptomatic farmers with high IgG levels against other agricultural fungi, than in the control group . On the other hand, the development of IgG antibodies to the fungi in asthmatic farmers remained unclear because of a discrepancy between the ELISA and ELIFA results . Cross-reactivity between Fusarium species was detected . CONCLUSIONS: The results indicate that Finnish farmers are exposed to W . sebi and Fusarium species in their work environment to a greater extent than has earlier been evaluated with air sampling and microbiologic methods.

Annu Rev Microbiol, 1998, 52, 779 - 806
Cooperative organization of bacterial colonies: from genotype to morphotype; Ben-Jacob E et al.; In nature, bacteria must often cope with difficult environmental conditions . To do so they have developed sophisticated cooperative behavior and intricate communication pathways . Utilizing these elements, motile microbial colonies frequently develop complex patterns in response to adverse growth conditions on hard surfaces under conditions of energy limitation . We employ the term morphotype to refer to specific properties of colonial development . The morphologies we discuss include a tip-splitting (T) morphotype, chiral (C) morphotype, and vortex (V) morphotype . A generic modeling approach was developed by combining a detailed study of the cellular behavior and dynamics during colonial development and invoking concepts derived from the study of pattern formation in nonliving systems . Analysis of patterning behavior of the models suggests bacterial processes whereby communication leads to self-organization by using cooperative cellular interactions . New features emerging from the model include various models of cell-cell signaling, such as long-range chemorepulsion, short-range chemoattraction, and, in the case of the V morphotype, rotational chemotaxis . In this regard, pattern formation in microorganisms can be viewed as the result of the exchange of information between the micro-level (the individual cells) and the macro-level (the colony).

APMIS, 1998 Nov, 106(11), 1041 - 8
Quantification of Bordetella pertussis in clinical samples by colorimetric detection of competitive PCR products; Erlandsson A et al.; Quantification of microorganisms is an important part of the normal diagnostic work of a clinical microbiology laboratory . Traditionally the diagnosis of pertussis is subject to a yes or no approach with no quantitative dimension . This can, however, be of interest as a factor when judging the risk of a patient spreading the bacterium and as a research tool . The aim of the present study was to develop a PCR-based quantitative assay for Bordetella pertussis DNA in clinical nasopharyngeal aspirates by combining a quantitative PCR with a colorimetric detection principle, DIANA (detection of immobilised amplified nucleic acid) . A competitor to the PCR target sequence in IS-481, containing a lac-operator, was constructed and calibrated, and a test protocol prepared . A total of 46 clinical nasopharyngeal aspirates, previously diagnosed using a standard nested PCR assay and quantified by culture, were analysed by the quantitative PCR . The method showed acceptable precision and accuracy considering that it estimates the total number of bacterial genomes while culture detects viable bacteria . Recognised advantages were the simple colorimetric detection, the inborn indication of a working PCR assay, and the possibility of obtaining results even when partial inhibition of the PCR assay was seen . In addition, the quantitative PCR result can be obtained within one day compared to 3-10 days for culture . The present results and the qualities of the quantitative PCR suggest that this assay will be a useful complement in routine diagnostics and in research.

Biotechnol Annu Rev, 1998, 4, 75 - 112
Modified hemoglobin blood substitutes: present status and future perspectives; Chang TM; Biotechnological techniques of cross-linking and microencapsulation of hemoglobin result in blood substitutes that can replace red blood cells . Unlike red blood cells they can be sterilized by pasteurization, ultrafiltration and chemical means . This removes microorganisms responsible for AIDS, hepatitis, etc . Since they are free of red blood cell blood group antigens, there is no need for cross-matching or typing . This saves time and facilities and allows on-the-spot transfusion such as the infusion of salt solution . Furthermore, they can be stored for a long time . Hemoglobin for modification can be extracted from human red blood cells . Other sources of hemoglobin include bovine hemoglobin and recombinant human hemoglobin . Clinical trials are ongoing testing the possible uses of cross-linked hemoglobin in cardiac, orthopedic, trauma and other types of surgery . It is also being tested for the replacement of lost blood in severe bleeding due to trauma or other causes . Cross-linked hemoglobins are first generation blood substitutes that only fulfil some of the functions of red blood cells . New generations of more complete red blood cell substitutes are being developed . These include cross-linked hemoglobin-catalase-superoxide dismutase and microencapsulated hemoglobin-enzyme systems.

Wien Klin Wochenschr, 1998 Nov 27, 110(22), 796 - 801
Receptor and non-receptor mediated formation of superoxide anion and hydrogen peroxide in neutrophils of intensive care patients; Manhart N et al.; Generation of reactive oxygen intermediates (ROI) has been implicated in tissue damage in a variety of disease states including sepsis and trauma . On the other hand, generation of ROI in polymorphonuclear granulocytes (PMN) presents a crucial element in the defence of the host against invading microorganisms . In the present study we investigated the generation of superoxide anions (O2-) and hydrogen peroxide (H2O2) by neutrophils (PMN)5 of 17 critically ill patients treated at a intensive care unit (ICU) after polytrauma (n = 6), heart operation (n = 6) or during septic shock (n = 5) using flow cytometry . O2- production of PMN from ICU patients was significantly lower (p < 0.01) than that in healthy volunteers (HV) during non-receptor mediated stimulation with phorbol-myristate-acetate (PMA) but higher (p < 0.001) during receptor mediated stimulation with formylmethionine-leucine-phenylalanine (FMLP) . H2O2 generation of PMN from ICU patients was increased after stimulation with FMLP (p < 0.01) and remained unchanged after stimulation with PMA . Patients in septic shock had lower O2(-)-generation of PMN than did injured patients and patients after heart operations . We conclude that receptor mediated formation of O2- and H2O2 is stimulated in ICU patients . However, in patients in septic shock O2(-)-generation decreases, which potentially might contribute to the immunoparalysis present in septic shock.

Minerva Stomatol, 1998 Nov, 47(11), 613 - 6
{Benign maxillofacial mucormycosis . Report of a case and review of the literature}; Cangiano G et al.; Mucormycosis is a rare and often lethal infection caused by an opportunistic fungus of the Phycomycetes class . This microorganism is a saprophytic aerobial fungus common in nature and in oral mucosae, nose, paranasal sinus and throat . Mucormycosis has been described in various clinical forms: rhinocerebral, pulmonary, systemic, cerebral and cutaneous, always in immunodepressed patients, with rapid evolution and high rate of mortality . However, rare cases involving maxillofacial area are described in healthy patients with benign evolution and good prognosis as in a case observed at the Department of Maxillofacial Surgery of the University of Naples "Federico II".

Biochem Biophys Res Commun, 1998 Dec 18, 253(2), 407 - 14
A region of the cellobiohydrolase I promoter from the filamentous fungus Trichoderma reesei mediates glucose repression in Saccharomyces cerevisiae, dependent on mitochondrial activity; Carraro DM et al.; The upstream activating region that controls cellulose-induced expression of the glucose-repressible cellobiohydrolase I gene (UARcb1) of the filamentous fungus Trichoderma reesei is shown to mediate transcription and glucose repression of a reporter gene in Saccharomyces cerevisiae, a unicellular microorganism that lacks the genes required for the utilization of cellulose . Glucose-controlled transcription mediated by UARcb1 requires the products of the genes SNF1 and SSN6, a protein kinase and a repressor, respectively, that regulate glucose-repressible yeast genes . Previously, it has been shown that mitochondrial function is implicated in cellobiohydrolase I gene expression in T . reesei and this sensitivity to the metabolic state of the mitochondria was shown to be transcriptionally controlled by the 5'-flanking sequence of the cbh1 gene {Abrahao-Neto et al . (1995) Biochemistry 34, 10456-10462} . Remarkably, transcription of the reporter gene controlled by UARcb1 in S . cerevisiae also showed a requirement for active mitochondria, suggesting that a common mechanism involving mitochondrial activity controls glucose-repressible genes in both microorganisms .

Anim Reprod Sci, 1998 Dec 31, 54(2), 65 - 73
Sanitary status of oocytes and embryos collected from heifers experimentally exposed to Leptospira borgpetersenii serovar hardjobovis; Bielanski A et al.; In a preliminary trial and three experiments, a total of 30 Holstein heifers were experimentally infected with a culture of Leptospira borgpetersenii serovar hardjobovis via one or more routes (uterine, cervical supraconjunctival, intranasal) and oviductal and uterine fluids recovered post-mortem or in vivo following superovulation with FSH . All routes of administration were effective in establishing Leptospira infection in the reproductive tract and Leptospira were identified in the oviductal and uterine fluids of all 30 heifers by microscopy . The incidence of infection was confirmed by positive identification of serum antibodies by the microscopic agglutination test (MAT) . Twenty-one samples of the embryos (n = 59) recovered were cultured using bacteriological procedures and all tested negative for the infectious microorganism . Using polymerase chain reaction (PCR) assay, however, showed that 29% (7/24) of morula and blastocyst stage embryos, and one out of 29 oocytes tested positive for the presence of leptospiral DNA . A single oocyte or embryo collected from the infected heifers was inoculated intravenously to 26 test heifers . None of the test heifers developed antibody titers to Leptospira . It was concluded that, despite the presence of leptospires in the reproductive tract of donor animals and the association of leptospiral DNA with uterine stage embryos, the transmission of this disease is unlikely to occur by transfer of in vivo produced embryos in the bovine.

Drug Dev Ind Pharm, 1998 Jul, 24(7), 589 - 97
Recent approaches in insulin delivery; Trehan A et al.; Insulin remains indispensable in the management of diabetes mellitus since its discovery in 1921 . The foreignness of early available porcine and bovine insulin led to the development of human insulin by transpeptidation and biosynthesis in microorganisms . Needle phobia and stress of multiple daily injections led to the investigation and exploitation of all promising routes, ranging from nasal to rectal, by a wide variety of devices and delivery systems . This article describes the development of human insulin, various routes for delivery of insulin (including oral, nasal, buccal, rectal, and pulmonary), and various devices for regulated, safe, and convenient insulin delivery . The article reviews some recent advances in insulin delivery such as the bioresponsive and self-regulated insulin delivery system.

Braz J Med Biol Res, 1998 Sep, 31(9), 1129 - 32
Use of a cysteine proteinase from Carica candamarcensis as a protective agent during DNA extraction; Genelhu MS et al.; We describe the use of a plant cysteine proteinase isolated from latex of Carica candamarcensis as a protective agent during isolation of bacterial DNA following growth in culture of these cells . Between 100 to 720 units of proteinase (1 microgram = 6 units) afforded good DNA protection when incubated with various kinds of microorganisms . Agarose gel electrophoresis showed that the resulting DNA was similar in size to DNA preparations obtained by treatment with proteinase K . The viability of the resulting material was checked by PCR amplification using species-specific primers . After standing at room temperature (25 degrees C) for 35 days, the enzyme lost 10% of its initial activity . The enzyme stability and good yield of DNA suggest the use of this proteinase as an alternative to proteinase K.

Appl Environ Microbiol, 1999 Jan, 65(1), 327 - 9
2-Bromoethanesulfonate, sulfate, molybdate, and ethanesulfonate inhibit anaerobic dechlorination of polychlorobiphenyls by pasteurized microorganisms
Ye D, Quensen JF 3rd, Tiedje JM, Boyd SA.
Dechlorination of Aroclor 1242 by pasteurized microorganisms was inhibited by 2-bromoethanesulfonate (BES), sulfate, molybdate, and ethanesulfonate . Consumption of these anions and production of sulfide from BES were detected . The inhibition could not be relieved by hydrogen . Taken together these results suggest that pattern M dechlorination is mediated by spore-forming sulfidogenic bacteria . These results also suggest that BES may inhibit anaerobic dechlorination by nonmethanogens by more than one mechanism.

Appl Environ Microbiol, 1999 Jan, 65(1), 138 - 42
Ergosterol content in various fungal species and biocontaminated building materials
Pasanen AL, Yli-Pietila K, Pasanen P, Kalliokoski P, Tarhanen J.
This paper reports the ergosterol content for microbial cultures of six filamentous fungi, three yeast species, and one actinomycete and the ergosterol levels in 40 samples of building materials (wood chip, gypsum board, and glass wool) contaminated by microorganisms . The samples were hydrolyzed in alkaline methanol, and sterols were silylated and analyzed by gas chromatography-mass spectrometry . The average ergosterol content varied widely among the fungal species over the range of 2.6 to 42 &mgr;g/ml of dry mass or 0.00011 to 17 pg/spore or cell . Ergosterol could not be detected in the actinomycete culture . The results for both the fungal cultures and building material samples supported the idea that the ergosterol content reflects the concentration of filamentous fungi but it underestimates the occurrence of yeast cells . The ergosterol content in building material samples ranged from 0.017 to 68 &mgr;g/g of dry mass of material . A good agreement between the ergosterol concentration and viable fungal concentrations was detected in the wood chip (r > 0.66, P </= 0.009) and gypsum board samples (r > 0.48, P </= 0.059), whereas no relationship between these factors was observed in the glass wool samples . For the pooled data of the building materials, the ergosterol content correlated significantly with the viable fungal levels (r > 0.63, P < 0.0001) . In conclusion, the ergosterol concentration could be a suitable marker for estimation of fungal concentrations in contaminated building materials with certain reservations, including the underestimation of yeast concentrations.

Acta Microbiol Immunol Hung, 1998, 45(3-4), 323 - 8
Biological effects of microorganisms and their substances in mice; Anderlik P et al.; In our experiments we evidence from several aspects that the normal microbial flora has a permanent and life-long immune modulating role in conventional organisms and a stimulating effect both on specific and non-specific defense . However, in case of artificial interventions (stress, drugs) affecting the organism, existence of the normal flora may have an adverse effect on it (endotoxin effect, bacterial translocation) . The immunomodulants show a stimulating effect mainly in organisms with undeveloped immune system, and their effects are independent from the presence or absence of the microbial flora . With ageing, effect of immunomodulants can change and become indifferent or even suppressive . Dose-dependence of stimulating or suppressing effect of immunomodulants may be related to their non-immunological effects (endotoxin effect, bacterial translocation) . Finally, on the basis of our experiments, we consider the Gf mouse suitable for examining the effect of a given agent in the practice, on the one hand, and for observing the host organism's reactions, free from the influence of the normal microbial flora, on the other . Along with the known physiological and pathological events, our results draw also attention to as distant fields as drug sensitivity, drug interactions influencing drug sensitivity . The authors put emphasis on importance of germfree environment during immunosuppressive treatments in humans and when making special examinations under experimental conditions.

Acta Microbiol Immunol Hung, 1998, 45(3-4), 317 - 22
Outlines of the immunological research in the Institute of Microbiology; Semmelweis Medical University; Szeri I et al.; The working group on immunology under the leadership of Pal Foldes began its activity with poliovirus studies during the severe epidemics of 1957 . It was he who first in Hungary isolated poliovirus strain from patients {1} . His colleague was Ilona, Szeri who had gained her first experiences in virology at Jozsef Sinkovics's virus laboratory . Then Zsuzsanna Banos and Piroska Anderlik joined them and became permanent members of the working group on immunology . Since 1965 with the leadership of Ilona Szeri, they have been conducting basic researches into immunology for over three decades at the Institute, with a wide sphere of collaborators . Research has been intended to acquire more thorough and precise knowledge of the role in immunobiology of the thymus and lymphoid system and of pathogenesis of the wasting syndrome as well as of interactions of the microorganisms and the organism . The most significant results are going to be summed up in the following.

J Mol Evol, 1999 Jan, 48(1), 49 - 58
Concordant evolution of a symbiont with its host insect species: molecular phylogeny of genus Glossina and its bacteriome-associated endosymbiont, Wigglesworthia glossinidia; Chen X et al.; Many arthropods with restricted diets rely on symbiotic associations for full nutrition and fecundity . Tsetse flies (Diptera: Glossinidae) harbor three symbiotic organisms in addition to the parasitic African trypanosomes they transmit . Two of these microorganisms reside in different gut cells, while the third organism is harbored in reproductive tissues and belongs to the genus Wolbachia . The primary symbiont (genus Wigglesworthia glossinidia) lives in differentiated epithelial cells (bacteriocytes) which form an organ (bacteriome) in the anterior gut, while the secondary (S) symbionts are present in midgut cells . Here we have characterized the phylogeny of Wigglesworthia based on their 16S rDNA sequence analysis from eight species representing the three subgenera of Glossina: Austenina (=fusca group), Nemorhina (=palpalis group), and Glossina (=morsitans group) . Independently, the ribosomal DNA internal transcribed spacer-2 (ITS-2) regions from these species were analyzed . The analysis of Wigglesworthia indicated that they form a distinct lineage in the gamma subdivision of Proteobacteria and display concordance with their host insect species . The trees generated by parsimony confirmed the monophyletic taxonomic placement of Glossina, where fusca group species formed the deepest branch followed by morsitans and palpalis groups, respectively . The placement of the species Glossina austeni by both the traditional morphological and biochemical criteria has been controversial . Results presented here, based on both the ITS-2 and the symbiont 16S rDNA sequence analysis, suggest that Glossina austeni should be placed into a separate fourth subgenus, Machadomyia, which forms a sister-group relationship with the morsitans group species.

Am J Respir Crit Care Med, 1999 Jan, 159(1), 143 - 8
Cytokine levels correlate with a radiologic score in active pulmonary tuberculosis; Casarini M et al.; Pulmonary tuberculosis is an infectious disease caused by Mycobacterium tuberculosis . This microorganism is capable of inducing a delayed hypersensitivity reaction in the lung, with subsequent expression of the disease . This reaction depends on the presence of different cytokines that exert specific functions . The aim of this study was to evaluate the presence and the concentrations of nine different modulators in bronchoalveolar lavage fluid (BALF) . For this purpose, 15 patients with active pulmonary tuberculosis were enrolled at the time of diagnosis, prior to institution of antituberculous therapy . All the patients demonstrated M . tuberculosis in the sputum, and their disease extention was defined by high-resolution computed tomography (HRCT) using a score which included the presence of six findings: miliary nodules, nodules < 10 mm, consolidation, ground glass, cavity and bronchial wall thickening . This score was more sensitive than an equivalent score calculated on the basis of chest radiology . HRCT score was calculated for each area of the two lungs in order to define the more and the less affected lung for each patient . The bronchoalveolar lavage (BAL) was performed in the more affected area for each lung . The HRCT total score for each washed area ranged between 1 and 15, and showed more significant differences between the more and less affected lungs (p = 0.0004) than those obtained with the individual radiologic findings (p ranged between 0.60 and 0 . 004) . The BAL concentrations of the nine cytokines evaluated for the more and less affected lungs were compared: interleukin-6 (IL-6), IL-8, IL-12, tumor necrosis factor-alpha (TNF-alpha), and interferon gamma (IFN-gamma) showed significant differences (p ranged between 0 . 016 and 0.0007) . In addition, each cytokine concentration was correlated with the HRCT score . Significant correlations were found with IL-12, IL-6, IL-8, IL-2, and TNF-alpha . The correlations between cytokines and HRCT total score were better than those observed with the individual radiologic findings . A correlation matrix for the different cytokines evaluated one against each other, has also been added to show common behavior of these modulators . A similar analysis was also performed for the radiologic abnormalities.

Oral Microbiol Immunol, 1998 Dec, 13(6), 373 - 7
Virulence of a polymicrobic complex, Treponema denticola and Porphyromonas gingivalis, in a murine model; Kesavalu L et al.; The effect of a polymicrobic infection employing Treponema denticola and Porphyromonas gingivalis in the murine lesion model was used to determine the synergistic virulence of these two periodontopathic bacteria . At high doses of P . gingivalis W50, addition of T . denticola in the infection mixture had no effect on the formation and size of the spreading lesion caused by this microorganism . However, at low P . gingivalis challenge doses, T . denticola significantly enhanced the virulence of P . gingivalis compared with monoinfection of this microorganism . A potential role of the trypsin-like protease enzyme activity of P . gingivalis in this synergistic virulence was tested using P . gingivalis mutants deficient (i.e., BEI) or devoid (i.e., NG4B19) of this protease activity . These findings demonstrated that T . denticola-P . gingivalis complexes exhibit enhanced virulence in this model and that even using a polymicrobic challenge infection, the trypsin-like protease activity was important to P . gingivalis virulence expression.

Semin Cancer Biol, 1998 Aug, 8(4), 275 - 83
Is Helicobacter pylori really the cause of gastric cancer?
Nyren O.
Since 1994, when the International Agency for Research on Cancer (IARC) designated Helicobacter pylori a human carcinogen, a considerable number of new studies have examined the association of this microorganism with risk of gastric cancer . The aim of this review was to critically evaluate current evidence of a causal relationship between the infection and gastric cancer in humans, taking these new studies into account . A MEDLINE search for the years 1982 through March 1998 yielded eight cohort studies, 40 case-control studies and eight ecologic studies . They were divided into four categories according to the weight of the evidence produced . In the category producing the strongest evidence, the cohort studies, five out of eight studies (including the three that formed the basis for the IARC decision) found a statistically significant excess risk of gastric cancer among the infected with odds ratios ranging between 2.8 and 6.0 . Two cohort studies showed a non-significant tendency towards a positive association, but with point estimates indicating no more than a 50-60% excess risk among the H . pylori seropositive, and one apparently well-performed cohort study was completely negative . The two population-based case-control studies published to date found statistically non-significant odds ratios no higher than 1.3 and 1.4 . Thus, the evidence of a strong causal link between H . pylori infection and gastric cancer has, if anything, become less convincing . Recent studies seem to indicate that the strength of the association may vary with type of H . pylori strain, and possibly presence of effect-modifying co-factors in the host and/or the environment . Future studies need to identify high-risk constellations of carcinogenic strains and unfavorable co-factors to make targeted prophylaxis cost-effective.

Clin Infect Dis, 1998 Dec, 27(6), 1394 - 400
Use of an immunotherapeutic vaccine to treat a life-threatening human arteritic infection caused by Pythium insidiosum; Thitithanyanont A et al.; A 14-year-old Thai boy presented because of a history of headache, mandibular swelling, and facial nerve palsy . A microorganism identified as Pythium insidiosum was cultured from the mandibular abscesses . Despite treatment with amphotericin B, iodides, ketoconazole, and surgery, the infection progressed . Magnetic resonance imaging (MRI) and magnetic resonance angiography (MRA) of the neck revealed an aneurysm in the external carotid artery . The aneurysm was removed . MRA performed later showed stenosis of the internal carotid artery . Immunotherapy was recommended as a last resort . One hundred microliters of the P . insidiosum vaccine was subcutaneously injected into the patient's left shoulder, and 14 days later a similar dose was administered . Four weeks following the first vaccination, the patient's headache had disappeared, the facial swellings had dramatically diminished, the cervical lymph node had shrunk, and the proximal left internal carotid artery stenosis had significantly improved . One year after the vaccinations, the boy was considered clinically cured.

Emerg Infect Dis, 1998 Oct-Dec, 4(4), 581 - 91
Bacterial symbiosis in arthropods and the control of disease transmission; Beard CB et al.; Bacterial symbionts may be used as vehicles for expressing foreign genes in arthropods . Expression of selected genes can render an arthropod incapable of transmitting a second microorganism that is pathogenic for humans and is an alternative approach to the control of arthropod-borne diseases . We discuss the rationale for this alternative approach, its potential applications and limitations, and the regulatory concerns that may arise from its use in interrupting disease transmission in humans and animals.

Am Ind Hyg Assoc J, 1998 Dec, 59(12), 831 - 41
The adaptation of existing personal inhalable aerosol samplers for bioaerosol sampling; Kenny LC et al.; Health-related monitoring of bioaerosol exposures in the workplace should ideally be carried out using size-selective personal samplers that separate the aerosol into biologically relevant size fractions and allow both quantification and identification of the microorganisms present in each fraction . As a first stage in the development of personal bioaerosol samplers a number of collection substrates were assessed for their ability to maintain the viability of the collected microorganisms, so that subsequent culturing and species identification may be carried out . The substrates were tested with bioaerosols of varying robustness, consisting of Saccharomyces cerevisiae cells, Escherichia coli cells, and Penicillium expansum spores, aerosolized under controlled environmental conditions . The survival of microorganisms on each test substrate, assessed on the basis of the culturable fractions of cells recovered, was compared with that of microorganisms collected in a reference glass cyclone sampler . These bioefficiency tests identified the substrate combinations with the potential to fulfill personal sampler design criteria . The substrates were then subjected to further development to evaluate and optimize their particle size selection characteristics . The outcome of this work is two prototype personal bioaerosol samplers in which size-selective substrates are adapted for use in existing designs of personal inhalable sampler . This offers an effective and low-cost solution to personal monitoring of bioaerosol exposures in the workplace.

Pediatr Dent, 1998 Nov-Dec, 20(7), 386 - 94
Pediatric bone marrow transplantation: oral complications and recommendations for care; da Fonseca MA; Bone marrow transplantation (BMT) has become an increasingly common treatment option for those patients who have a disease that affects the bone marrow (BM) directly or indirectly . Because of the level of immunosuppression achieved in BMT, any problems the pediatric patient presents in the oral cavity can become life-threatening and increase the length of hospital stay, the patient's discomfort, and the treatment costs . The oral cavity is a reservoir for microorganisms thus by reducing their number through optimal care, immunosuppressed patients may decrease their chance of a life-threatening systemic infection from an oral source . Many BMT teams believe that toothbrushing increases the risk of bacteremia and bleeding; however, problems are more likely to arise when patients are not compliant with good oral hygiene habits . It is vital to educate the caretaker and the child about the importance of oral care in order to minimize discomfort and maximize the chances for a successful transplant . This paper discusses the important and unique role that pediatric dentistry has in the multiprofessional BMT team to help bring about a successful outcome through the prevention and treatment of the acute oral complications often seen in these patients.

J Bacteriol, 1999 Jan, 181(1), 78 - 82
Two distinct mechanisms cause heterogeneity of 16S rRNA; Ueda K et al.; To investigate the frequency of heterogeneity among the multiple 16S rRNA genes within a single microorganism, we determined directly the 120-bp nucleotide sequences containing the hypervariable alpha region of the 16S rRNA gene from 475 Streptomyces strains . Display of the direct sequencing patterns revealed the existence of 136 heterogeneous loci among a total of 33 strains . The heterogeneous loci were detected only in the stem region designated helix 10 . All of the substitutions conserved the relevant secondary structure . The 33 strains were divided into two groups: one group, including 22 strains, had less than two heterogeneous bases; the other group, including 11 strains, had five or more heterogeneous bases . The two groups were different in their combinations of heterogeneous bases . The former mainly contained transitional substitutions, and the latter was mainly composed of transversional substitutions, suggesting that at least two mechanisms, possibly misincorporation during DNA replication and horizontal gene transfer, cause rRNA heterogeneity.

Eur Respir J, 1998 Nov, 12(5), 1141 - 6
Alveolar lining fluid regulates mononuclear phagocyte 5-lipoxygenase metabolism; Phare SM et al.; The enzyme 5-lipoxygenase (5-LO) catalyses the synthesis of leukotrienes (LT), which are important in phagocytosis and killing of microorganisms . The alveolar macrophage (AM), the primary resident defender of the alveolar space, has a greater capacity for LT synthesis than its precursor, the peripheral blood monocyte (PBM) . This study investigated whether the alveolar lining fluid (ALF) upregulates LT synthetic capacity in mononuclear phagocytes . Rat AM, peritoneal macrophages (PM) and ALF were obtained by lavage from pathogen-free animals . Human PBM were isolated from normal subjects . 5-LO metabolism and expression were measured with and without ALF . Rat ALF increased 5-LO metabolism (136.4+/-15.1% of control) in cultured PBM . This was associated with increased 5-LO activating protein (FLAP) (357+/-29.5 %), and 5-LO expression (188+/-31.3%) . Culture of AM for 3 days resulted in a greater decrement in LTB4 synthesis (LTB4 15.4+/-6.9% of day 1) than in PM (54.7+/-8.3% of day 1), suggesting a greater dependence of AM 5-LO metabolism on ALF . 5-LO and FLAP expression decreased to a greater degree in AM than PM in culture . Furthermore, AM cultured with ALF maintained their LT synthetic capacity, FLAP and 5-LO expression compared with control cells cultured in medium alone . In conclusion, alveolar lining fluid increased 5-lipoxygenase metabolism in peripheral blood monocytes and maintained it in cultured alveolar macrophages, by a mechanism of increased 5-lipoxygenase and 5-lipoxygenase activating protein expression . This may boost host defence capabilities.

Wei Sheng Wu Xue Bao, 1997 Apr, 37(2), 142 - 7
{Study of the relationship between the control of environmental microorganism and infection of patients with leukemia after trasplantation of bone marrow}; Zhu S et al.; After the transplantation of bone marrow, patients with leukemia are easily infected by kinds of microorganism and die . In this paper, F-mice with the 60Co-gamma irradiation (maximum lethal dose) were transplanted bone marrow, then control the microorganism in the environment . Morever the laminar flow wards for the leukemia patient of bone marrow transplantation were designed according to the data combined with the clinic condition . There is no any infection in twelve patients with bone marrow transplantation from 1989 to 1993.

Structure, 1998 Dec 15, 6(12), 1587 - 99
Crystal structure of quinolinic acid phosphoribosyltransferase from Mmycobacterium tuberculosis: a potential TB drug target; Sharma V et al.; Background: . Mycobacterium tuberculosis is the single most deadly human pathogen and is responsible for nearly three million deaths every year . Recent elucidation of the mode of action of isoniazid, a frontline antimycobacterial drug, suggests that NAD metabolism is extremely critical for this microorganism . M . tuberculosis depends solely on the de novo pathway to meet its NAD demand . Quinolinic acid phosphoribosyltransferase (QAPRTase), a key enzyme in the de novo biosynthesis of NAD, provides an attractive target for designing novel antitubercular drugs . Results: . The X-ray crystal structure of the M . tuberculosis QAPRTase apoenzyme has been determined by multiple isomorphous replacement at 2.4 A resolution . Structures of the enzyme have also been solved in complex with the substrate quinolinic acid (QA), the inhibitory QA analog phthalic acid (PA), the product nicotinate mononucleotide (NAMN), and as a ternary complex with PA and a substrate analog, 5-phosphoribosyl-1-(beta-methylene)pyrophosphate (PRPCP) . The structure of the nonproductive QAPRTase-PA-PRPCP Michaelis complex reveals a 5-phosphoribosyl-1-pyrophosphate-binding site that is different from the one observed in type I phosphoribosyltransferases (PRTases) . The type II PRTase active site of QAPRTase undergoes conformational changes that appear to be important in determining substrate specificity and eliciting productive catalysis . Conclusions: . QAPRTase is the only known representative of the type II PRTase fold, an unusual alpha/beta barrel, and appears to represent convergent evolution for PRTase catalysis . The active site of type II PRTase bears little resemblance to the better known type I enzymes.

Crit Rev Immunol, 1998, 18(6), 545 - 68
Immune deficits induced by strenuous exertion under adverse environmental conditions: manifestations and countermeasures; Shephard RJ et al.; A brief description is given of the various laboratory and clinical manifestations of immune suppression that arise when strenuous exertion must be carried out in the face of a negative energy balance, shifts of circadian rhythm, sleep deprivation, psychological stressors, and exposure to hostile environments (extremes of heat or cold, high or low ambient pressures, and hyper- or hypo-gravity conditions) . From the operational viewpoint, immune suppression could impair both physical and mental performance by increasing susceptibility to opportunistic microorganisms . It is also likely to increase susceptibility to sepsis following trauma or extensive burns, and has occasionally predisposed to fatal myocarditis . The effects of such challenges are complex, in part because of interactions between the various stressors . It is thus important to investigate the impact and to devise appropriate countermeasures with the full physical and intellectual resources of a defense environmental research laboratory . Existing knowledge of the topic is reviewed, and suggestions are made for research that may lead to new and more effective countermeasures.

Enferm Infecc Microbiol Clin, 1998, 16 Suppl 1, 52 - 60
{Intestinal parasitic infections and leishmaniasis in patients with HIV infection}; Moreno-Camacho A et al.; Intestinal parasite infections are very frequent in HIV patients with severe immunodeficiency (CD4 < 100/mm3) causing chronic diarrhea and malabsorption in the majority of cases . The most frequent microorganisms are microsporidia and Cryptosporidium parvum while Cyclospora cayetanensis and Isospora belli are more prevalent in subtropical and tropical areas and rare in industrialized areas . The diagnosis can be obtained by stool examination (differences in size and form of cysts), although microsporidia is frequently demonstrated by intestinal biopsy and/or duodenal aspirate . The treatment with cotrimoxazole for C . cayetanensis and I . belli is very effective and does not present any problems in the acute phase, however, due to a high percentage of relapses the treatment must be maintained while the patient is in a severe immunodeficiency state . E . intestinalis usually responds satisfactorily to albendazole while E . bieneusi is resistant to some drugs except in some cases (albendazole, atovaquone ad fumagillin) . C parvum is also resistant to most medicaments but shows an adequate or partial clinical: response to paramomicine (< 50%) . When there is no response, it is advised to administer octreotide since in half the cases the response is positive either total or partial . Nowadays with the use of protease inhibitors in the antiretroviral treatment a decrease in the incidence of these infections has been observed (microsporidia and C . parvum) even in the stools samples taken from the patients who had them before . As primary prophylaxis for C . parvum, it is better to avoid been exposed to the microorganism taking into account the 1997 preventive measures recommended by the USPHS/IDSA Prevention of Opportunistic Infections Working Group . The coinfection Leishmania-HIV is frequent in the mediterranean area . The most common specie is L . infantum . The incidence is most frequent in immunosuppressed patients (CD4 < 200 mm3) and in parenteral drug addicts . The symptomatology is similar to the one from immunocompetent patients, although in some cases it appears to be subclinical . A chronic development with relapses is frequent . The most effective diagnostic method for the finding of the parasites is thru bone marrow puncture and the culture in Novy-McNeal-Nicolle (NNN) medium . Serological tests have a low sensibility and the PCR is useful in asymptomatic cases, for therapeutical control and in relapses . The treatment is similar to that of immunocompetent patients, using primarily antimonials or amphotericine B (standard or lipid or liposomal forms) . Relapses are very frequent, therefore, it is important to perform a secondary prophylaxis . However, no treatment has been completely effective . Mortality rate is high (approximately 25%) during the first month after diagnosis . This fact may be related to the severe immunodeficiency state and/or to the toxicity of the drugs used . The main priority for the future is to find a first line treatment with higher efficacy, decrease in relapses and a lower toxicity.

Med Clin (Barc), 1998 Oct 31, 111(14), 521 - 4
{Cefixime versus amoxicillin plus netilmicin in the treatment of community-acquired non-complicated acute pyelonephritis}; Moreno-Martinez A et al.; BACKGROUND: Community-acquired non-complicated acute pyelonephritis (APN) is a frequent, occasionally serious infection (around 20% of the cases are bacteremic) that usually requires hospital admission . The third generation oral cephalosporins which are active against more than 95% of E . coli strains should allow the outpatient management of these patients . OBJECTIVE: To evaluate the bacteriological and clinical efficacy of oral cefixime in comparison to amoxicilin plus netilcilin in the treatment of APN . PATIENTS AND METHODS: Patients older than 18 years affected by APN were included in a fourteen month prospective study . According to a random numbers chart, the patients received cefixime (400 mg/24 h in a single daily dose for 12 days) or amoxicilin (1 g/8 h per os) plus netilmicin (4 mg/kg/24 h in a single intramuscular daily dose) during five days followed by 7 days of an oral treatment chosen according to the susceptibility pattern of isolated microorganism . RESULTS: Sixty-one patients received cefixime and 65 amoxicillin plus retilmicin . There were no significant differences between both groups of patients . Thirty-two patients presented bacteremia (25.4%) . The mean (SD) eak and trough concentrations of netilmicin were 11.4 (2.8) mg/l and 0.38 (0.4) mg/l, respectively . Clinical response was favorable in 97% of patients treated with cefixime and in 98% of those treated with amoxicilin plus netilmicin (p = NS) . The infection recurred in 10 out of 59 patients (16.9%) in the cefixime arm of the study and in 9 out of 64 patients (14%) treated with amoxicillin plus netilmicin (p = NS) . Tolerance to the study drugs was good in both arms of the study, and renal function remained normal . CONCLUSION: Cefixime seems to be an acceptable alternative to the regimens containing an aminopenicillin and an aminoglycoside for the treatment of community-acquired non-complicated APN.

Hum Genet, 1998 Oct, 103(4), 415 - 8
Selective complement C1s deficiency caused by homozygous four-base deletion in the C1s gene; Inoue N et al.; The complement system plays an important role in defense mechanisms by promoting the adherence of microorganisms to phagocytic cells and lysis of foreign organisms . Deficiencies of the first complement components, C1r/C1s, often cause systemic lupus erythematosus-like syndromes and severe pyogenic infections . Up to now no genetic analysis of the C1r/C1s deficiencies has been carried out . In the present work, we report the first genetic analysis of selective C1s deficiency, the patient having a normal amount of C1r . C1s RNA with a normal size was detected in patient's subcutaneous fibroblasts (YKF) by RNA blot analysis and RT-PCR . The amount of C1s RNA was approximately one-tenth of the RNA from the human chondrosarcoma cell line, HCS2/8 . In contrast, the levels of C1r and beta-actin RNA of YKF were similar to that of HCS2/8 . Sequence analysis of C1s cDNA revealed a deletion at nucleotides 1087-1090 (TTTG), creating a stop codon (TGA) at position 94 downstream of the mutation site . Direct sequencing of the gene between the primers designed on intron 9 and exon 10 indicated the presence of the deletion on exon 10 of the gene . Quantitative Southern blot hybridization suggested the mutation was homozygous . The 4-bp deletion on exon 10 was also found in the patient's heterozygous mother who had normal hemolytic activity.

Ned Tijdschr Geneeskd, 1998 Aug 1, 142(31), 1778 - 81
{Human granulocytic ehrlichiosis, a tick-borne disease}; Ijdo JW et al.; A 69-year-old male presented at a first-aid department in Connecticut (USA) with severe headache, fever and myalgia of three days' duration . Just before he became ill, an engorged tick had been noted on his back and removed . Laboratory results included a decreased white cell count and platelet count and elevated transaminases . So-called morulae consisting of microorganisms were detected in a peripheral blood smear of the day of admission . Treatment for human granulocyte ehrlichiosis with doxycycline for two weeks resulted in prompt and full recovery and after four weeks repeat laboratory tests were all within normal limits . Human granulocyte ehrlichiosis should be considered in a patient with a recent tick bite who develops fever, headache and myalgias, in the presence of leukopenia or thrombocytopenia, even in Western Europe.

Microb Ecol, 1998 Nov, 36(3), 362 - 371
A Comparison of the Use of In Vitro-Transcribed and Native rRNA for the Quantification of Microorganisms in the Environment; McMahon KD et al.; Abstract Nearly full-length, small subunit (SSU) rRNA was transcribed in vitro from clones of SSU rDNA genes . Comparing the use of in vitro-transcribed and native rRNA indicated that, when in vitro-transcribed rRNA was used as a standard for quantitative hybridizations with oligonucleotide probes, the population was consistently underestimated . The population abundance was expressed as a percentage of specific target SSU rRNA (determined with a specific oligonucleotide probe), relative to the total SSU rRNA (measured with a universal probe) . Differences in hybridization signals could be related to specific probe target locations and rRNA denaturation conditions, suggesting that higher order structure is important in quantitative membrane hybridizations . Therefore, in vitro-transcribed rRNA cannot always be used for the absolute quantification of microbial populations, but can be employed as a standard to quantify shifts in population abundance over time, and to compare community structure in various environments.

Microb Ecol, 1998 Nov, 36(3), 336 - 348
Microbial Transport, Survival, and Succession in a Sequence of Buried Sediments; Kieft TL et al.; Abstract Two chronosequences of unsaturated, buried loess sediments, ranging in age from <10,000 years to >1 million years, were investigated to reconstruct patterns of microbial ecological succession that have occurred since sediment burial . The relative importance of microbial transport and survival to succession was inferred from sediment ages, porewater ages, patterns of abundance (measured by direct counts, counts of culturable cells, and total phospholipid fatty acids), activities (measured by radiotracer and enzyme assays), and community composition (measured by phospholipid fatty acid patterns and Biolog substrate usage) . Core samples were collected at two sites 40 km apart in the Palouse region of eastern Washington State, near the towns of Washtucna and Winona . The Washtucna site was flooded multiple times during the Pleistocene by glacial outburst floods; the Winona site elevation is above flood stage . Sediments at the Washtucna site were collected from near surface to 14.9 m depth, where the sediment age was approximately 250 ka and the porewater age was 3700 years; sample intervals at the Winona site ranged from near surface to 38 m (sediment age: approximately 1 Ma; porewater age: 1200 years) . Microbial abundance and activities declined with depth at both sites; however, even the deepest, oldest sediments showed evidence of viable microorganisms . Same-age sediments had equal quantities of microorganisms, but different community types . Differences in community makeup between the two sites can be attributed to differences in groundwater recharge and paleoflooding . Estimates of the microbial community age can be constrained by porewater and sediment ages . In the shallower sediments (<9 m at Washtucna, <12 m at Winona), the microbial communities are likely similar in age to the groundwater; thus, microbial succession has been influenced by recent transport of microorganisms from the surface . In the deeper sediments, the populations may be considerably older than the porewater ages, since microbial transport is severely restricted in unsaturated sediments . This is particularly true at the Winona site, which was never flooded.

Microb Ecol, 1998 Nov, 36(3), 231 - 238
N2-Fixing Microbial Consortia Associated with the Ice Cover of Lake Bonney, Antarctica; Olson JB et al.; Abstract Nitrogen (N) availability is a key nutritional factor controlling microbial production in Antarctic freshwater and soil habitats . Since there are no significant sources of biologically available N entering these ecosystems, nitrogen fixation may be a major source of "new" N supporting primary and secondary production . The role of N2 fixation was examined in cyanobacteria-dominated microbial aggregates embedded in the permanent ice cover of Lake Bonney, McMurdo Dry Valley (Victoria Land) lakes area, and in cyanobacterial mats found in soils adjacent to the ice edge . Nitrogenase activity was extremely low compared to temperate and tropical systems, but N2 fixation was found at all study sites . N2 fixation occurred under both dark and light conditions, indicating the potential involvement of both phototrophic and heterotrophic diazotrophs . Nitrogenase activity measurements (acetylene reduction assay) and molecular characterization (PCR amplification of nifH fragments) demonstrated a diverse and periodically active (when liquid water is present) diazotrophic community in this arid, nutrient-limited environment . As a result of the close proximity to other microorganisms and the nutritional constraints of this environment, these diazotrophs may be involved in mutually beneficial consortial relationships that enhance their growth when water is available.

Exp Cell Res, 1998 Dec 15, 245(2), 290 - 3
The density of a homogeneous population of cells controls resetting of the program for swarmer formation in the unicellular marine microorganism Noctiluca scintillans; Sato MS et al.; Noctiluca scintillans is a luminescent marine dinoflagellate . The life cycle of Noctiluca consists of a vegetative stage and a swarmer stage . The swarmer stage of Noctiluca is initiated by formation of a swarmer-mother cell instead of binary fission of vegetative cells . We studied the formation of swarmers under various conditions and became convinced that the cells have a strict program for the formation of swarmers which starts to operate in every cell after a defined number of cell cleavages . The probability that the program will be executed appeared to be affected by the presence of other cells . In other words, a high density of cells suppressed the expression of the program . Suppression was achieved by resetting the mechanism and was related to the number of cell divisions . Our findings provide one of the simplest examples of a mechanism by which a large population produces individuality in a group of genetically homogeneous organisms .

Immunol Rev, 1998 Oct, 165, 267 - 77
Induction of peripheral CD8+ T-cell tolerance by cross-presentation of self antigens; Miller JF et al.; There is now convincing evidence that CD8+ T cells can be activated by professional antigen-presenting cells which present antigens derived from non-lymphoid tissues in association with MHC class I molecules in the draining lymph nodes . This mechanism, referred to as cross-presentation, enables the immune system to respond to those microorganisms that infect only non-lymphoid tissues . Consistent with this view, cross-presentation was found to focus on antigens expressed in high concentrations and those released from dying cells, which can be expected to result from viral infections . Recent evidence, however, demonstrates that high dose self antigens can be cross-presented constitutively, resulting in the activation of autoreactive CD8+ T cells . This does not lead to auto immunity under physiologic conditions, but to CD95-mediated deletion of the T cells . Cross-presentation can thus engage a well-defined pathway of antigen-induced T-cell death and purge the immune system of autoreactive CD8+ T cells . Low dose self antigens are not cross-presented and are consequently ignored . The immune system therefore uses two strategies to avoid CD8+ T-cell-mediated autoimmunity in the periphery: deletion of autoreactive CD8+ T cells responding to high dose self antigens and ignorance of self antigens expressed at low concentrations.

Antonie Van Leeuwenhoek, 1998 May, 73(4), 315 - 9
Decreased susceptibility of Malassezia furfur to UV light by synthesis of tryptophane derivatives; Mayser P et al.; Recently, tryptophane (Trp)-dependent synthesis of pigments and fluorochromes in Malassezia furfur was described . The possible significance of this metabolic pathway for the microorganism remains to be explored . Since the upper parts of the human epidermis are a natural habitat of M . furfur, increased exposure to UV light may be hazardous . Five reference strains and one wild type strain of M . furfur were grown on m-Dixon agar, in which the nitrogen source peptone had been substituted either by pigment-inducing tryptophane or arginine . The yeast cells thus obtained were harvested after 6 days, washed with physiological saline and inoculated on to the modified Dixon medium . Immediately after inoculation, the yeast cells were irradiated with UVA (100, 150 and 200 Jcm-2, single dose) or UVB (100, 500, 1000, 1500, 2000 mJcm-2, single dose; 500, 1500, 2500 mJcm-2 cumulative dose) . Irrespective of the primary nitrogen source (Trp or Arg), unexposed controls showed nearly identical cell yield after 5 days . In the case of irradiation, however, growth reduction of cells cultured on Trp was lesser than that of cells fed with arginine . High significance (p < 0.0001) was found especially with the upper UVA and UVB doses . Differences were also found among the individual test strains, the wild strain being most sensitive . One strain (CBS 6094) failed to produce pigment on Trp medium, and there were no differences in the growth behavior of subcultures of this strain fed with either arginine or tryptophane under irradiation . In conclusion, synthesis of pigments and fluorochromes by M . furfur implies the generation of potent UV filters in the UVA and UVB spectrum.

Am J Pathol, 1998 Dec, 153(6), 1717 - 22
Cryptosporidium parvum initiates inflammatory bowel disease in germfree T cell receptor-alpha-deficient mice; Sacco RE et al.; Flora-bearing mice with targeted disruption of T cell receptor (TCR)-alpha or -beta genes spontaneously develop intestinal inflammation with features similar to ulcerative colitis in humans . TCR-alpha-deficient mice maintained germfree or colonized with a limited number of intestinal bacteria failed to develop inflammatory bowel disease (IBD)-like lesions . Evidently, inflammation in these mice does not develop spontaneously or result from a generalized antigenic stimulation, but rather requires induction by a heretofore unidentified specific stimulus . We describe the development of IBD-like lesions in germfree TCR-alpha-deficient mice monoassociated with the protozoan Cryptosporidium parvum . Lesions were seen in distal ileum, cecum, and colon and were most severe in the cecum . A prominent leukocytic infiltrate within the lamina propria was a common characteristic of the lesions observed in the C . parvum-infected germfree TCR-alpha-deficient mice . The leukocytic infiltrate was composed of aggregates of B220+ cells, the majority of which expressed surface IgD (ie, conventional B lymphocytes) . It has been proposed that antigenic stimulation by a microorganism(s) is needed to initiate intestinal inflammation in TCR-alpha-deficient mice . Our results indicate that a single microbial species, C . parvum, is capable of triggering the development of IBD-like lesions in germfree TCR-alpha-deficient mice.

Trends Microbiol, 1998 Nov, 6(11), 449 - 53
Perspective: edible vaccines--a concept coming of age; Mor TS et al.; In addition to their traditional role as a source of natural medicines, it is now possible to genetically engineer plants to produce pharmaceuticals . Transgenic plants expressing antigens from pathogenic microorganisms offer many advantages as low-cost production systems and effective delivery systems for vaccines . This new technology might contribute to global vaccine programs and might have a dramatic impact on health care in developing countries.

Dig Surg, 1998, 15(5), 386 - 97
Role of intestinal permeability in monitoring mucosal barrier function . History, methodology, and significance of pathophysiology; Sun Z et al.; The intestinal barrier function is considered to play an important role in protecting the penetration of luminal antigens, associated with the development of secondary infection and sepsis and the initiation of the multiple organ dysfunction syndrome . The intestinal mucosal barrier against luminal macromolecules and microorganisms consists of both non-immunological and immunological defence mechanisms . The main constituents of the intestinal barrier are the endothelial and epithelial barriers . The epithelial barrier selectively restricts micromolecular permeation and almost completely restricts macromolecular permeation, while the endothelial barrier has a very limited restriction to micromolecules and only partly to macromolecules . Maintenance of the barrier depends on the integrity of cellular plasma membranes and tight junctions, as well as the elaboration of endothelial and epithelial secretory products . Focal denudation of the barrier results in permeation of potentially threatening luminal compounds including antigens, proteases, H+, bacteria and endotoxin, and also other factors chemotactic for inflammatory cells . By initiating inflammation and thus acting on subepithelial tissues, such factors can further influence endothelial and epithelial transport and barrier function . The repair of endothelial and epithelial injury is also complex, and both restitution and enhanced endothelial and epithelial cell proliferation are likely to be important . At present, however, mechanisms for intestinal epithelial and endothelial permeation, their alterations in disease and potential ways to prevent or repair injury, are still not fully elucidated.

Mt Sinai J Med, 1998 Oct-Nov, 65(5-6), 406 - 13
Judaism, genetic screening and genetic therapy; Rosner F; Genetic screening, gene therapy and other applications of genetic engineering are permissible in Judaism when used for the treatment, cure, or prevention of disease . Such genetic manipulation is not considered to be a violation of God's natural law, but a legitimate implementation of the biblical mandate to heal . If Tay-Sachs disease, diabetes, hemophilia, cystic fibrosis, Huntington's disease or other genetic diseases can be cured or prevented by "gene surgery," then it is certainly permitted in Jewish law . Genetic premarital screening is encouraged in Judaism for the purpose of discouraging at-risk marriages for a fatal illness such as Tay-Sachs disease . Neonatal screening for treatable conditions such as phenylketonuria is certainly desirable and perhaps required in Jewish law . Preimplantation screening and the implantation of only "healthy" zygotes into the mother's womb to prevent the birth of an affected child are probably sanctioned in Jewish law . Whether or not these assisted reproduction techniques may be used to choose the sex of one's offspring, to prevent the birth of a child with a sex-linked disease such as hemophilia, has not yet been ruled on by modern rabbinic decisions . Prenatal screening with the specific intent of aborting an affected fetus is not allowed according to most rabbinic authorities, although a minority view permits it "for great need." Not to have children if both parents are carriers of genetic diseases such as Tay-Sachs is not a Jewish option . Preimplantation screening is preferable . All screening test results must remain confidential . Judaism does not permit the alteration or manipulation of physical traits and characteristics such as height, eye and hair color, facial features and the like, when such change provides no useful benefit to mankind . On the other hand, it is permissible to clone organisms and microorganisms to facilitate the production of insulin, growth hormone, and other agents intended to benefit mankind and to cure and treat diseases.

Helicobacter, 1998 Dec, 3(4), 269 - 77
A novel method of extracting plasmid DNA from Helicobacter species; De Ungria MC et al.; BACKGROUND: Plasmids are extra-chromosomal DNA that may encode products that aid in virulence, pathogenesis, and the spread of antibiotic resistance among a wide spectrum of bacteria . Plasmids have been detected in Helicobacter pylori, H . felis, H . fennelliae, and H . cinaedi . However, no function has been attributed to the Helicobacter plasmids studied to date . Moreover, the characterization of plasmids in other Helicobacter species is an as yet unexplored area of research . Several laboratories have reported difficulties in the extraction and isolation of plasmid DNA from H . pylori and H . felis isolates due to the presence of large amounts of DNase, necessitating cumbersome and time-consuming purification steps . The development of a method for extracting plasmid DNA from Helicobacter species would be useful for future systematic studies of plasmids in this important group of microorganisms . MATERIALS AND METHODS: Eight H . pylori isolates, including the Sydney Strain SS1, three H . felis isolates, and one isolate each of H . hepaticus, H . bilis, H . mustelae, and H . rodentium, were screened for plasmid DNA using a novel method that includes a potassium xanthogenate-sodium dodecyl sulfate-phenol (XSP) buffer . A specific PCR targeting a highly conserved plasmid replication protein gene, repA, was used to confirm the presence of plasmids in the H . pylori isolates examined . The PCR primers used were designed based on the sequence of the H . pylori plasmid pHPM180 . To demonstrate the effectiveness of this method, plasmid DNA extracted from SS1 using XSP buffer was digested using three restriction enzymes (DdeI, SpeI and MaeIII) . The relative amount of DNA obtained using the protocol was also compared to the yield derived from four commercial kits commonly used in many laboratories . RESULTS: High and low molecular weight plasmids were extracted from H . pylori (n = 8) and H . felis (n = 3) isolates . The size range of these plasmids was from 3 kb to >16 kb . Attempts to isolate plasmids from H . hepaticus ATCC 51488, H . bilis ATCC 51630, H . rodentium MIT-95-2060, and H . mustelae NCTC 11574 were not successful, which was most likely due to the absence of endogenous plasmids from the strains examined . The relative amount of DNA obtained using the XSP buffer protocol was comparable to that obtained from commercial kits as assessed by direct examination of plasmid profiles on agarose gels . Plasmid DNA extracted from H . pylori SS1 using XSP buffer was successfully digested with restriction enzymes . CONCLUSION: This study reports the development of an efficient, inexpensive, and rapid method for extracting high and low molecular weight plasmids from Helicobacter species . Application of this novel method for the isolation and future characterization of plasmids from different Helicobacter species could promote a better understanding of the role of plasmids in the basic microbial physiology and ecology of this group of microorganisms.

Eur J Immunol, 1998 Nov, 28(11), 3541 - 51
Human epidermal Langerhans cells express the mannose-fucose binding receptor; Condaminet B et al.; Sugar receptors are being increasingly implicated in host-pathogen interactions because of their specific recognition of carbohydrates of microorganisms . The aim of this study was to identify sugar receptors expressed on the surface of human epidermal Langerhans cells (LC) . To this end, binding of a panel of fluorescent neoglycoproteins to human epidermal LC was analyzed by quantitative flow cytofluorometry after standardization with calibrated beads . We demonstrate that fresh human LC are the only cells isolated from healthy epidermis which express a membrane receptor specific for fucose-bovine serum albumin (BSA) and mannose-BSA . Quantitative analysis of mannose-BSA or fucose-BSA binding showed non-linear Scatchard plots, denoting the presence of high and moderate affinity binding on the LC surface . The binding parameters of these two ligands were not significantly different . Mannan, the yeast mannose-rich polysaccharide, fucose-BSA, mannose-BSA and free fucose are strong competitors of the three known ligands of the mannose receptor, i.e . fucose-BSA, mannose-BSA and fluorescein isothiocyanate dextran . The amount of mannose-BSA and fucose-BSA bound to LC was 1.5-fold higher at 37 degrees C than at 4 degrees C, suggesting an internalization process . Antibodies raised against the human macrophage mannose receptor strongly stained CD1a-positive LC but not CD1a-negative population . Taken together, our data demonstrate that fresh human LC are the only cells in the epidermis to express a fucose-mannose receptor on their surface.

Biosens Bioelectron, 1998 Nov 1, 13(10), 1127 - 40
An analysis of analyte-receptor binding kinetics for biosensor applications: influence of the fractal dimension on the binding rate coefficient; Sadana A; The diffusion-limited binding kinetics of analyte in solution to receptor immobilized on a biosensor surface is analysed within a fractal framework . Both a single- as well as a dual-fractal analysis are utilized . Antigen-antibody and analyte-receptor systems are analysed . For the antigen-antibody and analyte-receptor systems where a single- or a dual-fractal analysis was used, it is of interest to note that the binding rate coefficient and the fractal dimension exhibit changes in the same direction . The binding rate coefficient expressions obtained as a function of the fractal dimension indicate the high sensitivity of the binding rate coefficient with respect to the fractal dimension . For example, for a single-fractal analysis and for the binding of (a) 1 microM BSA in solution to the anti-BSA-protein fused to a biosensor surface, and for (b) the binding of m-xylene-saturated STE buffer solution to the microorganism immobilized to the fiber-optic end and covered with a polycarbonate membrane, the orders of dependence of the binding rate coefficient on the fractal dimension were 5.535 and 3.314, respectively . This emphasizes the importance of the degree of heterogeneity on the biosensor surface and its impact on the binding rate coefficient, k . This high sensitivity is also indicated for a dual-fractal analysis, at least for the binding rate coefficient, k2 . For example, during regeneration runs and for the binding of polymerase chain-reaction amplified DNA in solution to DNA capture protein immobilized on a fiber-optic biosensor, the order of dependence of k2 on Df2 was 3.399 . The fractional order of dependence of the binding rate coefficient(s) on the fractal dimension(s) further reinforces the fractal nature of the system . The binding rate coefficient expressions developed as a function of the fractal dimension for both single-fractal analysis and dual-fractal analysis systems are of particular value since they provide a means to better control biosensor performance by linking it to the heterogeneity on the surface . Also, the importance of the nature of the surface on biosensor performance is emphasized in a quantitative sense.

Curr Microbiol, 1999 Jan, 38(1), 33 - 6
Continually measured fungal profiles in sick building syndrome; McGrath JJ et al.; Buildings with indoor air quality (IAQ) complaints frequently have high airborne concentrations of Penicillium species, while buildings with few IAQ complaints have an indoor air (IDA) fungal ecology similar to outdoor air (ODA), where Cladosporium species is usually the dominant microorganism . These studies compared fungal air profiles, measured continually over 6 h in a documented sick building, in IDA in a room experiencing IAQ problems with fungal profiles measured concurrently in ODA . The dominant species collected at both sites were Penicillium species, Cladosporium species, and Alternaria species . In the IDA, Penicillium species were always the dominant organisms, ranging from 150 to 567 cfu/m3 (89.8-100% of the total fungi) . In the ODA, Cladosporium species were dominant in four samples (40.0-70.6%), while Penicillium species were dominant (52.7-79.6%) in two . These data demonstrate that, even though ODA fungal profiles are changing continuously, IDA fungal profiles in "sick" buildings tend to remain unchanged.

Res Vet Sci, 1998 Sep-Oct, 65(2), 111 - 4
Pharmacokinetics of ampicillin trihydrate following intravenous administration to water deprived Nubian goats; Elsheikh HA et al.; The present study reports the effect of water deprivation in the Nubian goat on the pharmacokinetics of ampicillin trihydrate following intravenous administration at a dose rate of 10 mg kg(-1) . Water deprivation for two days, which resulted in about 7.5 per cent loss in bodyweight, produced no significant effects on the pharmacokinetic parameters of the drug . In dehydrated goats that had lost an average of 9.8 per cent of their initial bodyweights, within three days of water deprivation, ampicillin showed significantly slower clearance values (P<0.001), without affecting significantly the pharmacokinetic parameters describing the distribution of the drug . After four days of water deprivation a dehydration level at which goats lost an average of 12.6 per cent bodyweight was reached, which resulted in significant alterations in the distribution and elimination pharmacokinetic parameters of ampicillin . The volume of the central compartment (Vc) and the volume of distribution at steady state (Vdss) were significantly decreased (P<0.01) leading to significant elevation in plasma concentrations of the drug (P<0.01) compared with the normally hydrated animals . In water deprived goats, significantly slower clearance of the drug (P<0.001) and reduced elimination rate constant (P<0.01) with the subsequent increases in the half-life time were also observed . Dosage intervals between the usual doses of ampicillin can be increased in dehydrated goats and concentrations which were high enough to kill susceptible microorganisms could still be achieved.

Can J Physiol Pharmacol, 1998 May, 76(5), 479 - 84
The gut as a potential trigger of exercise-induced inflammatory responses; Marshall JC; Multiple lines of evidence support the hypothesis that ischemia-induced impairment of normal gut barrier function, with loss of the normal tonic counterinflammatory influence of the gut immune system, contributes to the expression of uncontrolled inflammation in critically ill victims of trauma and overwhelming infection . The clinical syndrome known as the systemic inflammatory response syndrome (SIRS), which embodies uncontrolled inflammation in trauma and sepsis, is reproduced in its entirety by vigourous exercise, raising the possibility that the gut may also play a role in exercise-induced inflammation . Both strenuous exercise and systemic sepsis result in impairment of the normal gut barrier to luminal microorganisms, and result in elevated circulating levels of bacterial endotoxin . Under normal circumstances, the immune tissues of the gut-liver axis inhibit the expression of a host response to foodstuffs in the gut lumen, or to the indigenous microbial flora of the gut wall . This influence is an active, energy-requiring process . Both strenuous exercise and critical illness are associated with gut ischemia, providing a common biologic basis for the initiation of a dysregulated inflammatory response . Although direct evidence supporting or refuting the hypothesis that the gut can serve as a trigger for systemic inflammation following strenuous exercise is sparse, the similarities in the clinical manifestations of SIRS and exercise, and the promising results of prophylactic or therapeutic gut-directed strategies in critical illness, suggest that similar approaches may provide benefit for individuals engaged in extreme physical exercise.

Biochim Biophys Acta, 1998 Nov 27, 1425(3), 560 - 6
Disaccharides permeases: constituents of xylanolytic and mannanolytic systems of Aureobasidium pullulans; Lubomir K et al.; Aureobasidium pullulans, a yeast-like microorganism was found to produce mannobiose permease and xylobiose permease, transporting beta-1,4-mannobiose or beta-1,4-xylobiose into the cells from extracellular media . Both permeases are induced by the same inducers as the corresponding hemicellulolytic enzyme systems . Mannobiose permease is induced by beta-1,4-mannobiose or is formed in the cells growing on mannan (inducers of beta-mannanolytic enzymes) and xylobiose permease is induced by d-xylose, beta-1,4-xylobiose or during the growth on xylan (inducers of xylanolytic enzymes) . The permeases are energy dependent, synthesized de novo and their activities are inhibited by d-glucose . Since mannobiose permease transports beta-1,4-mannobiose, xylobiose permease appears to be less specific and transports beta-1,4-mannobiose, beta-1,4-xylobiose and methyl beta-d-xylopyranoside . Methyl beta-d-mannopyranoside or methyl beta-d-xylopyranoside serve as less efficient inducers of the corresponding permeases than beta-1,4-mannobiose or beta-1, 4-xylobiose.

Appl Environ Microbiol, 1998 Dec, 64(12), 4990 - 3
An immunological strategy To monitor In situ the phosphate starvation state in thiobacillus ferrooxidans
Varela P, Levican G, Rivera F, Jerez CA.
Thiobacillus ferrooxidans is one of the chemolithoautotrophic bacteria important in industrial biomining operations . During the process of ore bioleaching, the microorganisms are subjected to several stressing conditions, including the lack of some essential nutrients, which can affect the rates and yields of bioleaching . When T . ferrooxidans is starved for phosphate, the cells respond by inducing the synthesis of several proteins, some of which are outer membrane proteins of high molecular weight (70,000 to 80,000) . These proteins were considered to be potential markers of the phosphate starvation state of these microorganisms . We developed a single-cell immunofluorescence assay that allowed monitoring of the phosphate starvation condition of this biomining microorganism by measuring the increased expression of the surface proteins . In the presence of low levels of arsenate (2 mM), the growth of phosphate-starved T . ferrooxidans cells was greatly inhibited compared to that of control nonstarved cells . Therefore, the determination of the phosphorus nutritional state is particularly relevant when arsenic compounds are solubilized during the bioleaching of different ores.

Appl Environ Microbiol, 1998 Dec, 64(12), 4711 - 9
Degradation of phthalate and Di-(2-Ethylhexyl)phthalate by indigenous and inoculated microorganisms in sludge-amended soil
Roslev P, Madsen PL, Thyme JB, Henriksen K.
The metabolism of phthalic acid (PA) and di-(2-ethylhexyl)phthalate (DEHP) in sludge-amended agricultural soil was studied with radiotracer techniques . The initial rates of metabolism of PA and DEHP (4.1 nmol/g {dry weight}) were estimated to be 731.8 and 25.6 pmol/g (dry weight) per day, respectively . Indigenous microorganisms assimilated 28 and 17% of the carbon in {14C}PA and {14C}DEHP, respectively, into microbial biomass . The rates of DEHP metabolism were much greater in sludge assays without soil than in assays with sludge-amended soil . Mineralization of {14C}DEHP to 14CO2 increased fourfold after inoculation of sludge and soil samples with DEHP-degrading strain SDE 2 . The elevated mineralization potential was maintained for more than 27 days . Experiments performed with strain SDE 2 suggested that the bioavailability and mineralization of DEHP decreased substantially in the presence of soil and sludge components . The microorganisms metabolizing PA and DEHP in sludge and sludge-amended soil were characterized by substrate-specific radiolabelling, followed by analysis of 14C-labelled phospholipid ester-linked fatty acids (14C-PLFAs) . This assay provided a radioactive fingerprint of the organisms actively metabolizing {14C}PA and {14C}DEHP . The 14C-PLFA fingerprints showed that organisms with different PLFA compositions metabolized PA and DEHP in sludge-amended soil . In contrast, microorganisms with comparable 14C-PLFA fingerprints were found to dominate DEHP metabolism in sludge and sludge-amended soil . Our results suggested that indigenous sludge microorganisms dominated DEHP degradation in sludge-amended soil . Mineralization of DEHP and PA followed complex kinetics that could not be described by simple first-order equations . The initial mineralization activity was described by an exponential function; this was followed by a second phase that was described best by a fractional power function . In the initial phase, the half times for PA and DEHP in sludge-amended soil were 2 and 58 days, respectively . In the late phase of incubation, the apparent half times for PA and DEHP increased to 15 and 147 days, respectively . In the second phase (after more than 28 days), the half time for DEHP was 2.9 times longer in sludge-amended soil assays than in sludge assays without soil . Experiments with radiolabelled DEHP degraders suggested that a significant fraction of the 14CO2 produced in long-term degradation assays may have originated from turnover of labelled microbial biomass rather than mineralization of {14C}PA or {14C}DEHP . It was estimated that a significant amount of DEHP with poor biodegradability and extractability remains in sludge-amended soil for extended periods of time despite the presence of microorganisms capable of degrading the compound (e.g., more than 40% of the DEHP added is not mineralized after 1 year).

Appl Environ Microbiol, 1998 Dec, 64(12), 4650 - 7
A polyphasic approach To study the diversity and vertical distribution of sulfur-oxidizing thiomicrospira species in coastal sediments of the german wadden Sea
Brinkhoff T, Santegoeds CM, Sahm K, Kuever J, Muyzer G.
Recently, four Thiomicrospira strains were isolated from a coastal mud flat of the German Wadden Sea (T . Brinkhoff and G . Muyzer, Appl . Environ . Microbiol . 63:3789-3796, 1997) . Here we describe the use of a polyphasic approach to investigate the functional role of these closely related bacteria . Microsensor measurements showed that there was oxygen penetration into the sediment to a depth of about 2.0 mm . The pH decreased from 8.15 in the overlaying water to a minimum value of 7.3 at a depth of 1.2 mm . Further down in the sediment the pH increased to about 7.8 and remained constant . Most-probable-number (MPN) counts of chemolithoautotrophic sulfur-oxidizing bacteria revealed nearly constant numbers along the vertical profile; the cell concentration ranged from 0.93 x 10(5) to 9.3 x 10(5) cells per g of sediment . A specific PCR was used to detect the presence of Thiomicrospira cells in the MPN count preparations and to determine their 16S rRNA sequences . The concentration of Thiomicrospira cells did not decrease with depth . It was found that Thiomicrospira strains were not dominant sulfur-oxidizing bacteria in this habitat . Denaturing gradient gel electrophoresis (DGGE) of PCR-amplified 16S ribosomal DNA fragments followed by hybridization analysis with a genus-specific oligonucleotide probe revealed the diversity of Thiomicrospira strains in the MPN cultures . Sequence analysis of the highest MPN dilutions in which the genus Thiomicrospira was detected revealed that there were four clusters of several closely related sequences . Only one of the 10 Thiomicrospira sequences retrieved was related to sequences of known isolates from the same habitat . Slot blot hybridization of rRNA isolated from different sediment layers showed that, in contrast to the concentration of Thiomicrospira cells, the concentration of Thiomicrospira-specific rRNA decreased rapidly in the region below the oxic layer of the sediment . This study revealed the enormous sequence diversity of closely related microorganisms present in one habitat, which so far has been found only by sequencing molecular isolates . In addition, it showed that most of the Thiomicrospira populations in the sediment studied were quiescent.

Appl Environ Microbiol, 1998 Dec, 64(12), 4870 - 6
A new approach to utilize PCR-single-strand-conformation polymorphism for 16S rRNA gene-based microbial community analysis; Schwieger F et al.; Single-strand-conformation polymorphism (SSCP) of DNA, a method widely used in mutation analysis, was adapted to the analysis and differentiation of cultivated pure-culture soil microorganisms and noncultivated rhizosphere microbial communities . A fragment (approximately 400 bp) of the bacterial 16S rRNA gene (V-4 and V-5 regions) was amplified by PCR with universal primers, with one primer phosphorylated at the 5' end . The phosphorylated strands of the PCR products were selectively digested with lambda exonuclease, and the remaining strands were separated by electrophoresis with an MDE polyacrylamide gel, a matrix specifically optimized for SSCP purposes . By this means, reannealing and heteroduplex formation of DNA strands during electrophoresis could be excluded, and the number of bands per organism was reduced . PCR products from 10 of 11 different bacterial type strains tested could be differentiated from each other . With template mixtures consisting of pure-culture DNAs from 5 and 10 bacterial strains, most of the single strains could be detected from such model communities after PCR and SSCP analyses . Purified bands amplified from pure cultures and model communities extracted from gels could be reamplified by PCR, but by this process, additional products were also generated, as detected by further SSCP analysis . Profiles generated with DNAs of rhizosphere bacterial communities, directly extracted from two different plant species grown in the same field site, could be clearly distinguished . This study demonstrates the potential of the selected PCR-single-stranded DNA approach for microbial community analysis.

APMIS, 1998 Oct, 106(10), 928 - 34
Chlamydia pneumoniae and possible relationship to asthma . Serum immunoglobulins and histamine release in patients and controls; Larsen FO et al.; Chlamydia pneumoniae (C.pn.) is claimed to be of importance for the development of bronchial asthma in previously healthy individuals . This is a new and speculative theory . Earlier studies have mainly focused on C.pn . and exacerbation of asthma . If this new theory were true, one would expect titres of C.pn.-specific IgG to be higher or more common in patients compared with controls . It would also seem probable that pathobiological mechanisms as found in connection with other microorganisms could be demonstrated, i.e . presence of C.pn.-specific IgE and the capability of C.pn . to induce or enhance histamine release from basophil leukocytes . We therefore examined C.pn.-specific IgE, IgG and IgM in sera from 22 adults with bronchial asthma and 25 healthy controls . IgE was verified by passive sensitization of basophils from umbilical cord blood . The prevalence of IgE was approx . 69% and IgG approx . 23% in both groups . IgG-titres were between 1:16 and 1:64 in both groups . No IgM was found . Further, C.pn . could neither induce nor enhance histamine release from basophil leukocytes of patients or controls . We conclude that patients with bronchial asthma and healthy controls do not differ in relation to 1) C.pn.-specific IgE in sera, 2) the capability of C.pn . to induce or enhance histamine release from basophil leukocytes, since no such effect was found, or 3) previous C.pn . infection judged by the presence of specific IgG antibodies . Our results cannot support the theory that C.pn . is a cause of adult-onset asthma.

J Immunol Methods, 1998 Oct 1, 219(1-2), 187 - 93
A simple flow cytometry assay using dihydrorhodamine for the measurement of the neutrophil respiratory burst in whole blood: comparison with the quantitative nitrobluetetrazolium test; Richardson MP et al.; The neutrophil respiratory burst is essential for the host's ability to kill ingested microorganisms . Several flow cytometric assays have recently been developed to measure this process . These assays are largely unvalidated . In this study a whole blood flow cytometry assay using dihydrorhodamine 123 (DHR) as a substrate was compared with the quantitative nitrobluetetrazolium (NBT) test, an accepted measure of the earliest events in the respiratory burst . Because whole blood is used, the new assay is quicker and simpler than existing flow cytometry assays . Specimens as small as 0.1 ml can be used which makes the assay ideal for use in neonates and young children . There was a high degree of correlation between the DHR assay and the quantitative NBT test (r(s) = 0.76, P < 0.01) . It is concluded that the whole blood DHR assay is an accurate and sensitive measure of the respiratory burst.

Trends Biotechnol, 1998 Nov, 16(11), 475 - 82
Genetic manipulation of antitumor-agent biosynthesis to produce novel drugs; Salas JA et al.; Current methods of obtaining novel drugs may be complemented in the near future by the genetic engineering of antitumor-agent biosynthesis in microorganisms . Biosynthetic gene clusters from several antitumor pathways in actinomycetes are presently being characterized and expressed in order to generate novel drugs . Several novel hydroxylated and glycosylated antitumor-drug derivatives have been produced that show a relaxed substrate specificity for secondary-metabolic enzymes, which opens up the possibility of generating novel drugs by genetic manipulation.

Mol Gen Genet, 1998 Oct, 260(1), 102 - 7
Growth inhibition of Saccharomyces cerevisiae by the immunosuppressant leflunomide is due to the inhibition of uracil uptake via Fur4p; Fujimura H; The immunosuppressant leflunomide inhibits cytokine-stimulated proliferation of lymphoid cells in vitro and also inhibits the growth of the eukaryotic microorganism Saccharomyces cerevisiae . To elucidate the molecular mechanism of action of the drug, two yeast genes which suppress the anti-proliferative effect when present in multiple copies were cloned and designated MLF1 and MLF2 for multicopy suppressor of leflunomide sensitivity . DNA sequencing analysis revealed that the MLF1 gene is identical to the FUR4 gene, which encodes a uracil permease and functions to import uracil efficiently . The MLF2 was found to be identical to the URA3 gene . Excess exogenous uracil also overcomes the anti-proliferative effect of leflunomide on yeast cells . Uracil prototrophy also conferred resistance to leflunomide . Uracil uptake was inhibited by leflunomide . Thus, the growth inhibition by leflunomide seen in a S . cerevisiae ura3 auxotroph is due to the inhibition of the entry of exogenous uracil via the Fur4 uracil permease.

J Food Prot, 1998 Nov, 61(11), 1567 - 70
Risk assessment and economic analysis for managing risks to human health from pathogenic microorganisms in the food supply; Morales RA et al.; Risk managers increasingly face having to justify their decisions in allocating limited resources . These decisions may include prioritizing hazards, determining appropriate levels of safety, and identifying and selecting optimal risk reduction strategies . These decisions require making choices among alternatives, choices that may be difficult because they invariably involve trade-offs . Integrating risk assessment and economic analyses can aid decision making by determining the benefits and costs of alternative actions . Risk assessment and economic analysis provide the measurement tools that will facilitate intelligent, informed, risk management and will enable effective and efficient resource allocation decisions.

J Food Prot, 1998 Nov, 61(11), 1541 - 9
Growth and inactivation models to be used in quantitative risk assessments; van Gerwen SJ et al.; In past years many models describing growth and inactivation of microorganisms have been developed . This study is a discussion of the growth and inactivation models that can be used in a stepwise procedure for quantitative risk assessment . First, rough risk assessments are performed in which orders of magnitude for microbial processes are estimated by the use of simple models . This method provides an efficient way to find the main determinants of risk . Second, the main determinants of risk are studied more accurately and quantitatively . It is best to compare several models at this level, as no model is expected to be able accurately to predict microbial responses under all circumstances . By comparing various models the main determinants of risk are studied from several points of view, and risks can be assessed on a broad basis . If, however, process variations have a more profound effect on risk than the differences between models, it is most efficient to use the simplest model available . If relevant, the process variations can be stochastically described in the third level of detail . Stochastic description of the process parameters will however not change the conclusion on the usefulness of simple models in quantitative risk assessments . The proposed stepwise procedure that starts simply before going into detail provides a structured method of risk assessment and prevents the researcher from getting caught in too much complexity . This simplicity is necessary because of the complex nature of food safety . The principal aspects are highlighted during the procedure and many factors can be omitted since their quantitative effect is negligible.

J Biotechnol, 1998 Oct 19, 65(1), 3 - 14
Physiological investigations by image analysis; Pons MN et al.; Modern quantitative image analysis has been extensively used to characterize the morphology of microorganisms, especially those of the filamentous type . More recently physiological features have been quantified, making use of classical stains as well as fluorescent dyes . The potential of the technique is illustrated by a detailed analysis of the differentiation of Streptomyces ambofaciens . Three different staining procedures have been used to monitor the thinning and septation of hyphae (with propidium iodide staining), the leakage of cellular components through the membrane (with carbol gentian violet staining) and the respiration (with INT staining) in a batch submerged culture.

Zh Mikrobiol Epidemiol Immunobiol, 1998 Sep-Oct, (5), 67 - 70
{Anti-Trichomonas activity of metronidazole in the presence of immunobiological preparations}; Rubalskii OV et al.; The minimal doses of metronidazole, capable of the irreversible immobilization of Trichomonas in the presence of one antiprotozoan preparation and after the addition of recombinant tumor necrosis factor (TNF), recombinant gamma-interferon and complex immunoglobulin preparation (CIP) into the culture medium, were determined on 4 T.vaginalis isolates, obtained on day 2 after the inoculation of material from the mucous membrane of the urogenital organs of patients (incubation at 37 degrees C) . After 12-hour incubation of Trichomonas with immunobiological preparations their sensitivity to metronidazole increased 2-fold . After the simultaneous introduction of TNF, gamma-interferon and CIP into the culture medium, the sensitivity of Trichomonas to the action of metronidazole increased 5- to 7-fold . The introduction of an additional dose of TNF into the culture medium, but without CIP led to the preservation of the motility in a small number of these microorganisms . The use of human albumin instead of CIP at the same concentration (15 g/l) in the presence of TNF and gamma-interferon ensured the complete immobilization of Trichomonas in all isolates.

Am J Obstet Gynecol, 1998 Nov, 179(5), 1254 - 60
Microbial invasion of the amniotic cavity with Ureaplasma urealyticum is associated with a robust host response in fetal, amniotic, and maternal compartments; Yoon BH et al.; OBJECTIVE: Ureaplasma urealyticum is the microorganism most frequently isolated from the amniotic fluid of women with preterm labor and preterm premature rupture of the membranes, yet the significance of amniotic fluid infection exclusively caused by this microorganism is unclear . This study was conducted to examine the presence and intensity of the inflammatory response in the fetal, amniotic, and maternal compartments in patients with preterm premature rupture of membranes and amniotic fluid infection with U urealyticum . STUDY DESIGN: One hundred twenty patients with preterm premature rupture of the membranes who delivered preterm neonates (gestational age </=36 weeks) within 5 days of amniocentesis were included . Amniotic fluid was cultured for aerobic and anaerobic bacterias and mycoplasmas . The intensity of the inflammatory response was evaluated by amniotic fluid concentrations of interleukin-6, tumor necrosis factor-alpha, interleukin-1beta, amniotic fluid white blood cell count, histologic chorioamnionitis, and interleukin-6 concentrations of umbilical cord plasma at birth . Cytokines were measured by sensitive and specific immunoassays . RESULTS: The prevalence of a positive amniotic fluid culture in which the only microbial isolate was U urealyticum was 21% (25/120) and that of positive cultures with other or mixed microorganisms was 9% (11/120) . Intrauterine inflammatory response was significantly more intense in patients with positive amniotic fluid cultures limited to U urealyticum than in those with a negative culture (median and range of amniotic fluid interleukin-6, 13.4 {0.7-115.2} ng/mL vs 0.9 {0.001-137.2} ng/mL; median and range of amniotic fluid tumor necrosis factor-alpha, 85.5 {0.9-1600} pg/mL vs 2.4 {0-1142} pg/mL; median and range of amniotic fluid interleukin-1beta, 274.0 {0.3->80,000} pg/mL vs 3.4 {0-1449} pg/mL; median and range of amniotic fluid white blood cell count, 306 {0-19,764} cells/mm3 vs 3 {0-7956} cells/mm3; median and range of cord interleukin-6, 20.0 {2 . 3-1199.6} pg/mL vs 6.7 {0-5550} pg/mL; histologic chorioamnionitis, 100% {22/22} vs 42% {30/72}; P <.01 for each) but was similar to values of patients with a positive amniotic fluid culture for other bacteria or mixed microorganisms . CONCLUSION: Patients with preterm premature rupture of membranes and microbial invasion of the amniotic cavity with U urealyticum are associated with a robust host inflammatory response in the fetal, amniotic, and maternal compartments.

Artif Organs, 1998 Nov, 22(11), 958 - 65
Artificial cells with emphasis on cell encapsulation of genetically engineered cells; Chang TM; Artificial cells are prepared in the laboratory for medical and biotechnological applications . Encapsulated cells are being studied for the treatment of diabetes, liver failure, and other conditions . More recently, there have been extensive studies into the use of encapsulated genetically engineered cells for gene therapy . We recently found that daily orally administered artificial cells, each containing a genetically engineered microorganism, can lower the elevated urea level in uremic rats to normal levels . This may solve the final obstacle of the lack of an effective oral urea removal system for the simple and inexpensive oral treatment of uremia . This is important because 85% of the world's uremic population cannot afford standard dialysis . Other areas of artificial cell application include use in hemoperfusion . Red blood cell substitutes based on modified hemoglobin are already in Phase 3 clinical trials in patients . Artificial cells containing enzymes are being developed for clinical trial in hereditary enzyme deficiency disease and other diseases . They are also being investigated for drug delivery and for use in other applications in biotechnology, chemical engineering, and medicine.

Vnitr Lek, 1998 Mar, 44(3), 166 - 9
{Infections of the diabetic foot--etiopathogenesis and possible preventive strategies}; Mudrikova T et al.; The St . Vincent declaration defined the aim to achieve within the next five years a 50% reduction of the number of amputations on account of diabetic gangrene . This can be achieved by systematic application of preventive and therapeutic provisions in practice . The authors mention the most important pathogenetic factors leading to the development of lesions of the lower extremities in diabetics as well as the most frequent microorganisms participating in their infection . They remind also of the most important preventive measures to be taken by patients and physicians.

Mol Gen Mikrobiol Virusol, 1998, (3), 37 - 8
{HpyNI--a novel restriction endonuclease isolated from the pathogenic microorganism Helicobacter pylori}; Repin VE et al.; HpyNI is the first restriction endonuclease which has been isolated from pathogenic Helicobacter pylori . HpyNI, a new isoschizomer of ScrFI, recognizes and cleaves the palindromic sequence 5'CCNGG-3'.

J Infect Dis, 1998 Dec, 178(6), 1767 - 75
Sequence polymorphisms in the Pneumocystis carinii cytochrome b gene and their association with atovaquone prophylaxis failure; Walker DJ et al.; Atovaquone (Mepron, 566c80) is an effective agent against Pneumocystis carinii, which probably acts by binding to cytochrome b and inhibiting electron transport . To assess the possibility that atovaquone resistance might be developing, the genes for the cytochrome b from P . carinii sp . f . carinii and P . carinii sp . f . hominis were partially sequenced . Eight of 10 patient isolates had cytochrome b genes with the same amino acid sequence . The P . carinii cytochrome b genes from 2 of 4 patients who had atovaquone prophylaxis failure contained mutations resulting in amino acid changes in one of the ubiquinone (coenzyme Q) binding sites (Qo) . These mutations are homologous to mutations in other microorganisms that confer resistance to similar inhibitors . Variations in the sequence of the P . carinii cytochrome b gene suggest but do not prove the development of drug resistance.

Sheng Wu Yi Xue Gong Cheng Xue Za Zhi, 1997 Jun, 14(2), 164 - 9
{Microrough surface and its bio-effects of metallic biomaterials (II)--bio-effects of microrough surface of metallic biomaterials}; Wen X; As for bio-effect of microrough surface of metallic biomaterials, seven aspects are reviewed in this article: i.e., the relationship between microrough surface (MRS) and corrosion resistance, ion release rate; the relationship between MRS and inflammation; the relationship between MRS and epithelium cells, fibroblast cells; the relationship between MRS and soft tissue; the relationship between MRS and bone; the relationship between MRS and blood tissue; the relationship between MRS and microorganism, contamination, decontamination . To sum up, MRS has its advantages in biocompatibility.

Medicina (B Aires), 1998, 58(4), 367 - 73
{Physiopathologic effects of nitric oxide and their relationship with oxidative stress}; Carrizo PH et al.; Nitric oxide (NO.) is produced from L-arginine, as result of a reaction catalyzed by the enzyme nitric oxide synthase (NOS) . The reaction is the sole source of NO . in animal tissues . NO . can control physiological processes (or systems) such as (a) blood pressure; (b) relaxation of arterial smooth muscle; (c) platelet aggregation and adhesion; (d) neurotransmission; (e) neuroendocrine secretion . NO . contributes to the killing of pathogenic microorganisms and tumoral cells by phagocytes . NO . reacts with superoxide anion thus producing peroxynitrite, a cytotoxic ion capable of destroying many biological targets . The superoxide/peroxinitrite balance determines the ONOO- production and, accordingly, is essential for the development of hypertension, atherosclerosis, neurodegenerative diseases, viral infections, ischemia-reperfusion injury, and cancer.

Int J Pancreatol, 1998 Oct, 24(2), 111 - 6
Infected bile-induced acute pancreatitis in rabbits . The role of bacteria; Arendt T et al.; CONCLUSIONS: Bacteria species commonly found in bile of patients with choledocholithiasis render human bile toxic to the pancreas . The severity of infected bile-induced acute pancreatitis depends on the bacterial species . Infected bile-induced acute pancreatitis turns into a sterile inflammation within 10 d . BACKGROUND: Flow of bile into the pancreatic duct was proposed to cause some forms of gallstone pancreatitis . The development of bile-induced acute pancreatitis at physiologic ductal pressure is known to depend on the bacterial infection of bile . In this study, we investigated the effect of a variety of bacteria species commonly found in bile of patients with choledocholithiasis upon the pancreatic toxicity of human bile . The time-course of pancreatic infection in infected bile-induced acute pancreatitis was also analyzed . METHODS: In rabbits, the pancreatic duct was kept obstructed throughout the experiment . After 24 h, 50 microL of pancreatic juice was obtained from the congested pancreatic duct and replaced with the same quantity of infected human bile . Bile contained bacteria (10(7) microorganisms/microL) of species frequently found in choledochal secretions of patients with gallstone disease . Effects on pancreatic morphology were studied after 48 h . In another experiment, the number of Escherichia coli/mg of pancreatic tissue was determined in a time sequence study following exposure of the rabbit pancreatic duct to 50 microL E . coli-infected bile (10(7) microorganisms/mL) and temporary (12 h) or permanent duct obstruction . RESULTS: Sterile bile was not harmful to the pancreas . Infected bile caused an interstitial-edematous pancreatitis with occasional acinar necrosis . The severity of acute pancreatitis depended on the bacterial species . Following pancreatic duct exposure to E . coli-infected bile, there was complete clearance of the bacteria from the gland with a concomitant interstitial leukocyte infiltration within a period of 2-10 d.

J Travel Med, 1995 Mar 1, 2(1), 33 - 36
Cyclosporidia: A General Review; Himy R et al.; We have identified the first French cases of cyanobacterium-like bodies (CLB) or cyclosporidia in the feces of two immunocompetent patients who presented with a persistent diarrheal syndrome after a visit to India and Nepal.1 We take this opportunity to review the available data on this new microorganism.

Biochim Biophys Acta, 1998 Nov 19, 1408(2-3), 278 - 89
Structure, biologic properties, and expression of surfactant protein D (SP-D); Crouch EC; Surfactant protein D (SP-D) is a member of the family of collagenous host defense lectins, designated collectins . There is increasing evidence that SP-D, like SP-A, is an important component of the innate immune response to microbial challenge, and that it may participate in other aspects of immune and inflammatory regulation within the lung . SP-D binds to glycoconjugates and/or lipid moieties expressed by a wide variety of microorganisms and certain other organic particles, in vitro . Although binding may facilitate microbial clearance through aggregation or other direct effects on the organism, SP-D also has the capacity to modulate leukocyte function, and in some circumstances, to enhance their killing of microorganisms.

J Biol Chem, 1998 Nov 20, 273(47), 31463 - 70
Ammonium/methylammonium permeases of a Cyanobacterium . Identification and analysis of three nitrogen-regulated amt genes in synechocystis sp . PCC 6803; Montesinos ML et al.; Ammonium is an important nitrogen source for many microorganisms and plants . Ammonium transporters whose activity can be probed with {14C}methylammonium have been described in several organisms including some cyanobacteria, and amt genes encoding ammonium/methylammonium permeases have been recently identified in yeast, Arabidopsis thaliana, and some bacteria . The unicellular cyanobacterium Synechocystis sp . PCC 6803 exhibited a {14C}methylammonium uptake activity that was inhibited by externally added ammonium . Three putative amt genes that are found in the recently published complete sequence of the chromosome of strain PCC 6803 were inactivated by insertion of antibiotic resistance-encoding gene-cassettes . The corresponding mutant strains were impaired in uptake of {14C}methylammonium . Open reading frame sll0108 (amt1) was responsible for a high affinity uptake activity (Ks for methylammonium, 2.7 microM), whereas open reading frames sll1017 (amt2) and sll0537 (amt3) made minor contributions to uptake at low substrate concentrations . Expression of the three amt genes was higher in nitrogen-starved cells than in cells incubated in the presence of a source of nitrogen (either ammonium or nitrate), but amt1 was expressed at higher levels than the other two amt genes . Transcription of amt1 was found to take place from a promoter bearing the structure of the cyanobacterial promoters activated by the nitrogen control transcription factor, NtcA.

New Microbiol, 1998 Oct, 21(4), 379 - 89
Distribution of Synechococcus sp . and Synechococcus bacillaris in the waters of the Straits of Magellan (April 1995-early austral autumn); Caruso G et al.; During the last oceanographic cruise carried out in the Straits of Magellan (April 1995), a serological approach was used in order to determine the distribution and composition of the picophytoplankton community with respect to two cyanobacteria species, Synechococcus sp . and bacillaris, characterized respectively by phycoerythrin and phycocyanin as the main accessory photosynthetic pigment . In the period examined, the Straits were characterized by generally low concentrations of total picophytoplankton (10(5)-10(6) cells/l) . The qualitative composition of the community showed the prevalence of the species Synechococcus sp . in the Pacific basin, whereas S . bacillaris appears to be predominant in the central area . The immunofluorescence method proved to be effective in the study of the diversity of these microorganisms in aquatic environments.

Zentralbl Bakteriol, 1998 Oct, 288(2), 253 - 66
Prevalence of antibodies to tick-borne encephalitis virus and Borrelia burgdorferi sensu lato in samples from patients with abnormalities in the cerebrospinal fluid; Treib J et al.; Within the last few years, an increase in cases of tick-borne encephalitis (TBE) as well as an expansion of TBE-endemic regions have been noted in southern Germany . In 1994, a patient was diagnosed for the first time with TBE that had been acquired in Saarland . Up to this point, the Saarland had been considered TBE-free . In a retrospective study, we tested serum samples from 904 patients with abnormalities in the cerebrospinal fluid (CSF) for TBE antibodies . The IgG ELISA used (Immunozym-FSME-IgG, Immuno GmbH, Heidelberg, Germany) yielded 47 positive and 134 borderline sera . The percentage of positive sera showed a significant increase during the time period studied (1989-1994): One IgG-positive serum sample was also IgM-positive . Of the CSF samples, 2 were IgG-positive and 7 were borderline for IgG . In three patients, a positive intrathecal antibody index (IAI) was found, indicating an incrathecal antibody production . An analysis of the vaccination history of the patients showed that only 19% of the patients with a positive TBE IgG titre and only 5.9% of the borderline patients had been vaccinated against TBE . We compared 98 patients that tested positive or borderline for TBE IgG with 98 sex-and-age-matched patients that tested negative . The parameters studied included the patient's complaints upon discharge, the average duration of stationary treatment and 16 different neurological symptoms . We did not observe any significant differences between the two groups . We also tested the sera of 704 of the 904 patients for antibodies to Borrelia burgdorferi (Borrelia burgdorferi ELISA, Genzyme Virotech GmbH, Russelsheim, Germany) . 155 (22.0%) of the sera were IgG-positive, 136 (19.3%) were borderline, 32 patients (4.6%) had a positive intrathecal antibody index (IAI) . The fact that no patient with a clinically manifest case of TBE had acquired the disease in the Saarland indicates that the actual risk of acquiring an acute TBE in the Saarland is very low, despite the high percentage of samples that tested positive for IgG in the ELISA . The increase in the number of serum samples that tested positive for TBE IgG during the last years could be explained by an expansion of TBE regions into the Saarland, increasing vaccination of the population or more travel to endemic regions . The proportion of patients with IgG antibodies to Borrelia was 22% . Because only part of the patients suffered from an acute, clinically manifest borreliosis, and since the serum IgG titre had remained positive for many years after contact with the microorganisms, we suspected that a large percentage of the population would show signs of a clinically silent infection in their sera . 4.6% of the patients had a positive IAI quotient, a clear indication of neuroborreliosis.

Arch Dermatol Res, 1998 Sep, 290(9), 463 - 76
Genetics of psoriasis; Henseler T; Non-pustular psoriasis consists of two disease subtypes, type I and type II, which demonstrate distinct characteristics . Firstly the disease presents in different decades of life, in type I before the age of 40 years and later in type II . Secondly, contrasting frequencies of HLA alleles are found: type I patients express predominantly HLA-Cw6, -B57, and -DR7, whereas in type II patients HLA-Cw2 is overrepresented . Finally, familial inheritance is found in type I but not in type II psoriasis . The study of concomitant diseases in psoriasis contributes to deciphering the distinct patterns of the disease . Defence against invading microorganisms seems better developed in psoriatics than in controls . This evolutionary benefit may have caused the overall high incidence of psoriasis of 2% . Psoriasis is a multifactorial and heterogenetically inherited disease . The heterogeneity is evident by the diversity of genetically linked markers . The multifactorial component results from the observation of external trigger mechanisms, such as the Koebner phenomenon, stress and the intake of certain drugs . Twin studies have shown that environmental factors contribute to the onset of the disease . In type I psoriasis, special extended haplotypes such as EH57.1 (HLA-Cw6-B57-DRB1*0701-DQA1*0201-DQB1*0303) and EH65.1 (HLA-Cw8-B65-DRB1*0102-DQB1*0501) have been found to be increased . The application of microsatellite techniques has identified distinct positions on several chromosomes at which putative psoriasis genes may be located . Disease susceptibility genes are thought to be present on chromosomes 4q, 6p, 16q, 17q and 20p . Moreover, on chromosome 1q, genes regulating epidermal differentiation have been identified . Linkage to this area has been proposed . Furthermore, psoriasis gene loci on chromosomes 2, 8 and 20 have been suggested.

Trends Biotechnol, 1998 Oct, 16(10), 427 - 33
Signal-transduction cascades as targets for therapeutic intervention by natural products; Cardenas ME et al.; Many bacteria and fungi produce natural products that are toxic to other microorganisms and have a variety of physiological effects in animals . Recent studies have revealed that, in several cases, the targets of these agents are components of conserved signal-transduction cascades . This article looks at the mechanisms of action of five natural products--the immunosuppressants cyclosporin A, FK506 and rapamycin, and the antiproliferative agents wortmannin and geldanamycin . These mechanisms reveal the importance of signal-transduction cascades as targets for therapeutic intervention and the enormous utility of studies of natural-product action in simple model genetic systems.

Vet Rec, 1998 Oct 10, 143(15), 417 - 20
Diarrhoea in nursing piglets associated with coccidiosis: prevalence, microscopic lesions and coexisting microorganisms; Chae C et al.; A retrospective study was made of natural infections with Isospora suis in nursing piglets, recorded from April 1994 to May 1997, to determine the prevalence, microscopical lesions and other microorganisms associated with coccidiosis . One hundred and five (17.3 per cent) of the 605 nursing piglets submitted from 304 pig farms were diagnosed positive for coccidiosis . The affected piglets were from seven to 20 days old, with a mean age of 11.1 days . Coccidiosis occurred in each year but the incidence peaked in July (15 cases, 14.3 per cent), September (15 cases, 14.3 per cent), October (16 cases, 15.2 per cent) and November (18 cases, 17.1 per cent) and was lowest in May (no cases), August (two cases, 1.9 per cent) and June (four cases, 3.8 per cent) . Histopathologically, villous atrophy resulting from the necrosis and sloughing of epithelial cells was a prominent feature of infection with I suis . In 49.5 per cent of the nursing piglets, other enteropathogens were identified, Escherichia coli (47.6 per cent) and transmissible gastroenteritis virus (3.8 per cent) being the most commonly diagnosed . Forty-five of 50 E coli isolates associated with coccidiosis tested negative by polymerase chain reaction for enterotoxigenic virulence factors, such as fimbriae and enterotoxins.

Immunopharmacol Immunotoxicol, 1998 Nov, 20(4), 493 - 518
Functional changes in THP-1 human monocytic cells after stimulation with lipopolysaccharide of oral microorganisms and granulocyte macrophage colony stimulating factor; Baqui AA et al.; A human THP-1 monocyte cell line culture system has been utilized to observe the effect of granulocyte macrophage colony stimulating factor (GM-CSF) supplementation with lipopolysaccharide (LPS) of oral microorganisms to stimulate monocyte/macrophage functional activity . LPS of oral microorganisms, Fusobacterium nucleatum and Porphyromonas gingivalis was produced by phenol-water extraction and characterized . The phagocytosis assay was performed using F1TC labeled Saccharomyces yeast particles . Phagocytic functional activity was observed in 10-11% of resting THP-1 cells . Treatment of THP-1 cells with LPS of F . nucleatum or P . gingivalis increased the phagocytic activity of THP-1 cells 2-3 fold . GM-CSF significantly increased phagocytosis either alone or when supplemented with LPS of F . nucleatum or P . gingivalis . A chemotaxis assay was performed using a 48 well chemotaxis chamber . Chemotactic functional activity of THP-1 cells was increased 2-fold after 4 days of treatment with GM-CSF . Stimulation of THP-1 cells with LPS of F . nucleatum or P . gingivalis significantly reduced the chemotactic activity indicating the maturation towards a fixed macrophage . There were functional variations (chemotaxis and phagocytosis) in THP-1 cells in response to LPS of oral microorganisms following stimulation with GM-CSF.

Biochim Biophys Acta, 1998 Nov 8, 1442(2-3), 415 - 8
Saccharomyces cerevisiae MLF3/YNL074C gene, encoding a serine-rich protein of unknown function, determines the level of resistance to the novel immunosuppressive drug leflunomide; Fujimura HA; The immunosuppressant leflunomide inhibits the growth of cytokine-stimulated proliferation of lymphoid cells in vitro and also inhibits the growth of the eukaryotic microorganism, Saccharomyces cerevisiae . To elucidate the molecular mechanism of action of the drug, a yeast gene which suppresses the anti-proliferative effect when in increased copy number was cloned and designated MLF3 for multicopy suppressor of leflunomide sensitivity . DNA sequencing analysis revealed that the MLF3 gene is identical to the YNL074C gene which encodes a serine-rich protein of 452 amino acids . Disruption of the MLF3 gene caused increased sensitivity to the immunosuppressant leflunomide.

Hum Reprod, 1998 Oct, 13(1O), 2756 - 61
Ureaplasma urealyticum reduces motility and induces membrane alterations in human spermatozoa; Nunez-Calonge R et al.; The in-vitro effects of several concentrations of Ureaplasma urealyticum on the motility, membrane integrity and morphology of washed spermatozoa from healthy donors were studied . A significant reduction in sperm motility and signs of membrane alteration, directly related to U.urealyticum concentration and contact time were observed . Scanning electron microscopy examination showed masses of U . urealyticum attached to the head and middle piece of some of deformed spermatozoa . It is suggested that U.urealyticum is involved in sperm changes leading to male infertility, particularly when there is heavy U . urealyticum colonization or specific infections with this microorganism.

J Clin Gastroenterol, 1998 Oct, 27(3), 271 - 3
Simultaneous intestinal leishmaniasis and mycobacterial involvement in a patient with acquired immune deficiency syndrome; Velasco M et al.; Gastrointestinal involvement is reported in approximately 50% to 93% of patients with human immunodeficiency virus . It is frequently the result of coinfection with several microorganisms . Selective Leishmania intestinal involvement presents with atypical symptoms for visceral leishmaniasis, and may appear as a relapse or as the first manifestation of the disease . The authors present a patient with acquired immune deficiency syndrome who has a history of treated leishmaniasis and gastrointestinal infection by showed Mycobacterium avium intracellulare (MAI) . After the new onset of abdominal pain, an intestinal biopsy showed the presence of both MAI and Leishmania in duodenum . Intestinal infection by Leishmania must be included in the differential diagnosis in patients with a previous history of leishmaniasis or travel to an endemic area.

Antonie Van Leeuwenhoek, 1998 Apr, 73(3), 215 - 22
Surface chemical studies of Thiobacillus ferrooxidans with reference to copper tolerance; Das A et al.; A strain of Thiobacillus ferrooxidans was adapted to grow at higher concentrations of copper by single step culturing in the presence of 20 g/L (0.314 mol/L) cupric ions added to 9K medium . Exposure to copper results in change in the surface chemistry of the microorganism . The isoelectric point of the adapted strain (pI = 4.7) was observed to be at a higher pH than that of the wild unadapted strain (pI = 2.0) . Compared to the wild strain, the copper adapted strain was found to be more hydrophobic and showed enhanced attachment efficiency to the pyrite mineral . The copper adsorption ability of the adapted strain was also found to be higher than that of the wild strain . Fourier transform infrared spectroscopy of adapted cells suggested that a proteinaceous new cell surface component is synthesized by the adapted strain . Treatment of adapted cells with proteinase-K, resulted in complete loss of tolerance to copper, reduction in copper adsorption and hydrophobicity of the adopted cells . These observations strongly suggest a role played by cell surface modifications of Thiobacillus ferrooxidans in imparting the copper tolerance to the cells and bioleaching of sulphide minerals.

Semin Immunol, 1998 Oct, 10(5), 351 - 3
Innate immune recognition and control of adaptive immune responses; Medzhitov R et al.; The immune system of higher vertebrates consists of two components: innate and adaptive . The innate immune system relies on a set of germ-line encoded receptors that recognize conserved molecular patterns found only in microorganisms . The adaptive immune system uses somatically generated antigen receptors which are clonally distributed on the two types of lymphocytes: T cells and B cells . These antigen receptors are generated by random processes and, as a consequence, the general design of the adaptive immune system is based on clonal selection of lymphocytes expressing receptors with particular specificities . Here we discuss the essential role of the innate immune system in the clonal selection of lymphocytes and activation of the adaptive immune responses .

Infect Control Hosp Epidemiol, 1998 Oct, 19(10), 795 - 7
Mortality as an outcome in hospital-acquired pneumonia; Rello J et al.; The most common route of entry of pathogens into the lung in patients managed in the intensive-care unit is aspiration of contaminated oropharyngeal secretions or gastric contents . In intubated patients, the risk of this type of infection is particularly high . Knowledge of specific risk factors for specific microorganisms, along with the origin of acquisition (primary endogenous, secondary endogenous, or exogenous), will permit a more rational and effective method of prevention . Attributable mortality is highly dependent on the institution of a correct initial antibiotic choice, as well as the interaction between the virulence of the pathogen responsible and host defenses . However, survival in these patients is determined primarily by the degree of severity at the time of pneumonia diagnosis and the response to initial therapy . As a consequence, the number of preventable deaths is likely to be much smaller than the total . Therapy requires both supportive and specific measures . When diagnostic information becomes available, it permits the rescue of some patients with inadequate therapy or simplifies the spectrum of the empirical therapy . Initial antibiotic choice should be based on expected etiologic pathogens, while knowledge of local microbial epidemiology and susceptibility patterns is crucial.

Crit Rev Microbiol, 1998, 24(3), 273 - 80
Preventing the misuse of microorganisms: the role of the American Society for Microbiology in protecting against biological weapons; Berns KI et al.; The American Society for Microbiology's (ASM) involvement with issues surrounding biological weapons began during World War II and continues to the present time . The Public and Scientific Affairs Board (PSAB) of the ASM has played an important role in monitoring and responding to legislative and regulatory issues involving biological weapons . As this review makes apparent, there is no consensus of opinion among scientists on their role in biological defense research, or is it likely that there will ever be complete agreement . There is consensus that steps should be taken to prevent biological warfare and that openness of scientific research and global surveillance of disease outbreaks can significantly increase transparency for detecting development of biological weapons . The ASM recommends increased attention to and efforts directed toward global surveillance of disease outbreaks, not only to aid public health organizations in improving human health, but also to establish baseline data against which unusual disease outbreaks can be assessed . Issues of how best to increase global security and to achieve a scientifically based verification protocol of the Biological Weapons Convention are important and continue to be addressed by the ASM.

CLAO J, 1998 Oct, 24(4), 232 - 5
Surface deposits on frequent replacement and conventional daily wear soft contact lenses: a scanning electron microscopic study; Ilhan B et al.; PURPOSE: We performed a prospective study to compare the surface deposits on frequent replacement soft contact lenses with deposits on conventional daily wear soft contact lenses . METHODS: We fit two groups of young myopic patients with either conventional daily wear or frequent replacement soft contact lenses . Subjects in both groups wore their lenses on a daily wear basis and used a hydrogen peroxide/catalytic disk based care system . Contact lenses were obtained from patients in the frequent replacement group after 1 month of wear and from the conventional contact lens group after 12 months . Contact lenses from each group were examined with scanning electron microscopy and surface deposits were compared . RESULTS: Frequent replacement lenses were covered with significantly fewer deposits than conventional daily wear soft contact lenses (P = 0.0003) . No microorganisms were seen on frequent replacement contact lenses . Bacteria in the form of coccus on two contact lenses were seen in the other group . CONCLUSIONS: Surface deposits occur less often on frequent replacement lenses but they cannot be totally prevented . Surface deposit related contact lens complications may be expected to occur less frequently with the use of frequent replacement lenses.

Genome Res, 1998 Oct, 8(10), 1048 - 59
A comparative analysis of ABC transporters in complete microbial genomes; Tomii K et al.; The ABC transporter is a major class of cellular translocation machinery in all bacterial species encoded in the largest set of paralogous genes . The operon structure is frequently found for the genes of three molecular components: the ATP-binding protein, the membrane protein, and the substrate-binding protein . Here, we developed an "ortholog group table" by comparison and classification of known and putative ABC transporters in the complete genomes of seven microorganisms . Our procedure was to first search and classify the most conserved ATP-binding protein components by the sequence similarity and then to classify the entire transporter units by examining the similarity of the other components and the conservation of the operon structure . The resulting 25 ortholog groups of ABC transporters were well correlated with known functions . Through the analysis, we could assign substrate specificity to hypothetical transporters, predict additional transporter operons, and identify novel types of putative transporters . The ortholog group table was also used as a reference data set for functional assignment in four additional genomes . In general, the ABC transporter operons were strongly conserved despite the extensive shuffling of gene locations in bacterial evolution . In Synechocystis, however, the tendency of forming operons was clearly diminished . Our result suggests that the ancestral ABC transporter operons may have arisen early in evolution before the speciation of bacteria and archaea.

Arch Microbiol, 1998 Nov, 170(6), 405 - 10
Acclimation of the photosynthetic response of Chromatium vinosum to light-limiting conditions; Sanchez O et al.; The photosynthetic response of the purple sulfur bacterium Chromatium vinosum DSM 185 to different degrees of illumination was analyzed . The microorganism was grown in continuous culture, and samples were taken from the effluent of the culture and incubated at different irradiances to determine the specific rate of sulfur oxidation as a measure of the photosynthetic activity of the organism . The activities obtained were plotted as a function of the specific rate of light uptake, and for each set of data a photosynthesis equation was fitted, which allowed the estimation of Pmax (photosynthetic capacity), qk (the threshold irradiance for light limitation), and m (maintenance coefficient) . The results indicated that cells grown under light limitation are able to achieve higher photosynthetic activities than cells grown under light saturation . The photosynthetic capacity (Pmax) remained constant under all the conditions of illumination tested, while the maintenance expenses (m) were higher under light limitation . The parameter qk, on the contrary, decreased considerably at limiting irradiances.

J Thorac Imaging, 1998 Oct, 13(4), 282 - 8
Radiographic findings in patients with acquired immunodeficiency syndrome, pulmonary infection, and microbiologic evidence of Mycobacterium xenopi; Bankier AA et al.; The authors studied radiographs and clinical histories of 29 patients with acquired immunodeficiency syndrome, symptoms of pulmonary infection, and simultaneous microbiologic evidence of Mycobacterium xenopi in the respiratory tract . The presence, nature, and distribution of radiographic abnormalities were determined and analyzed in accord with clinical information . In 26 (90%) patients, M . xenopi was the only microorganism that could be isolated . Chest radiographs were normal in 13 patients (45%) and abnormal in 16 patients (55%) . Radiographic abnormalities were bilateral in 94% of cases and predominantly involved the lower lobes . Patchy peribronchial opacities (44%) and miliary nodules (24%) were the most common abnormalities . Reticular opacities and parenchymal consolidation were seen in 12% of patients . Pleural effusion was seen in 18% of patients . No patients had cavitations or adenopathy . There was no statistically significant difference regarding the mean age (38.7+/-7.3 years vs . 40.2+/-11.0 years), the duration of clinically evident human immunodeficiency virus infection (2.7+/-1.2 years vs . 2.8+/-1.4 years), and the mean of CD4 cell counts (50.6+/-15.3 cells/ml vs . 47.4+/-15.9 cells/ml) between the patients with and without abnormalities on chest radiographs . In patients with acquired immunodeficiency syndrome, pulmonary infection, and simultaneous microbiologic evidence of M . xenopi, chest radiographs can be normal in a substantial number of cases . When radiographic abnormalities are present, they differ from those seen in patient not infected with the human immunodeficiency virus who had pulmonary infection caused by M . xenopi and from patients with acquired immunodeficiency syndrome and pulmonary infection with nontuberculous mycobacteria other than M . xenopi . Although these findings are not specific, they may be of importance in the imaging of patients with acquired immunodeficiency syndrome, notably in areas where M . xenopi is endemic.

Appl Environ Microbiol, 1998 Nov, 64(11), 4313 - 6
Selection and characterization of microorganisms utilizing thaxtomin A, a phytotoxin produced by streptomyces scabies
Doumbou CL, Akimov V V, Beaulieu C.
Thaxtomin A is the main phytotoxin produced by Streptomyces scabies, a causal agent of potato scab . Thaxtomin A is a yellow compound composed of 4-nitroindol-3-yl-containing 2,5-dioxopiperazine . A collection of nonpathogenic streptomycetes isolated from potato tubers and microorganisms recovered from a thaxtomin A solution were examined for the ability to grow in the presence of thaxtomin A as a sole carbon or nitrogen source . Three bacterial isolates and two fungal isolates grew in thaxtomin A-containing media . Growth of these organisms resulted in decreases in the optical densities at 400 nm of culture supernatants and in 10% reductions in the thaxtomin A concentration . The fungal isolates were identified as a Penicillium sp . isolate and a Trichoderma sp . isolate . One bacterial isolate was associated with the species Ralstonia pickettii, and the two other bacterial isolates were identified as Streptomyces sp . strains . The sequences of the 16S rRNA genes were determined in order to compare thaxtomin A-utilizing actinomycetes to the pathogenic organism S . scabies and other Streptomyces species . The nucleotide sequences of the gamma variable regions of the 16S ribosomal DNA of both thaxtomin A-utilizing actinomycetes were identical to the sequence of Streptomyces mirabilis ATCC 27447 . When inoculated onto potato tubers, the three thaxtomin A-utilizing bacteria protected growing plants against common scab, but the fungal isolates did not have any protective effect.

Appl Environ Microbiol, 1998 Nov, 64(11), 4185 - 93
Evolution of a pathway for chlorobenzene metabolism leads to natural attenuation in contaminated groundwater
van der Meer JR, Werlen C, Nishino SF, Spain JC.
Complete metabolism of chlorinated benzenes is not a feature that is generally found in aerobic bacteria but is thought to be due to a novel recombination of two separate gene clusters . Such a recombination could be responsible for adaptation of a natural microbial community in response to contamination with synthetic chemicals . This hypothesis was tested in a chlorobenzene (CB)-contaminated aquifer . CB-degrading bacteria from a contaminated site were characterized for a number of years by examining a combination of growth characteristics and DNA-DNA hybridization, PCR, and DNA sequence data . The genetic information obtained for the CB pathway of the predominant microorganism, Ralstonia sp . strain JS705, revealed a unique combination of (partially duplicated) genes for chlorocatechol degradation and genes for a benzene-toluene type of aromatic ring dioxygenase . The organism was detected in CB-polluted groundwater by hybridizing colonies cultivated on low-strength heterotrophic media with probes for the CB pathway . Southern hybridizations performed to determine the organization of the CB pathway genes and the 16S ribosomal DNA indicated that CB-degrading organisms isolated from different wells at the site were identical to JS705 . Physiological characterization by the Biolog test system revealed some differences . The genes for the aromatic ring dioxygenase and dihydrodiol dehydrogenase of JS705 were detected in toluene and benzene degraders from the same site . Our results suggest that recent horizontal gene transfer and genetic recombination of existing genes between indigenous microorganisms were the mechanisms for evolution of the catabolic pathway . Evolution of the CB pathway seems to have created the capacity for natural attenuation of CB at the contaminated site.

Biochemistry (Mosc), 1998 Sep, 63(9), 1015 - 20
Polygalacturonase inhibiting protein in plant cell walls
Glinka EM, Protsenko MA.
Polygalacturonase inhibiting protein (PGIP) is localized in plant cell walls and plays an important role both in pectic substance metabolism and in prevention of the penetration of phytopathogenic microorganisms . Apparently, PGIP is responsible for the specificity of cell--cell interactions during pollination or inoculation by fungi nonpathogenic for the particular plant . PGIPs from different plants share a basic common structure . They are rather thermostable glycoproteins enriched with leucine and contain about 20% carbohydrates; the molecular weight varies between 37-54 kD . The synthesis of PGIP is encoded by one gene, and its expression is stimulated by injury and fungal infection . The resistance of plant tissues to infection frequently correlates with PGIP expression and with inhibiting action on fungal PG . Thus, PGIP is believed to be useful for gene engineering to obtain transgenic plants resistant to fungal infection or retaining commercial value during storage.

Res Microbiol, 1998 Sep, 149(8), 577 - 83
Detection of microorganisms in vessel wall specimens of the abdominal aorta: development of a PCR assay in the absence of a gold standard; Meijer A et al.; A procedure in which the "Invitrogen Easy-DNA" kit was followed by a silica-based method for the isolation of DNA was developed for extraction of PCR-inhibitor-free DNA from up to 300 mg of human vessel wall tissue . Optimally designed PCR assays were developed for the detection of at least one infected cell in this amount of tissue . Details of the procedure are given for the detection of DNA of Chlamydia pneumoniae, cytomegalovirus and herpes simplex virus type 1 and type 2 in human vessel walls . The procedure can serve as a reference method or as a gold standard when a high-performance method is needed.

Nippon Ishinkin Gakkai Zasshi, 1998, 39(4), 187 - 92
{Evaluation of new method for diagnosis of opportunistic fungal infection}; Hashimoto A et al.; New methods for the possible presence DNA specific for Aspergillus or Trichosporon species were developed . In aspergillus PCR, Aspergillus l8S rRNA encoding gene was amplified from five strains of Aspergillus species by the nested PCR but not from other microorganisms . Results of preliminary investigation of this method demonstrated efficient detections of Aspergillus species in serum samples of rats model of aspergillosis and 29 patients with invasive aspergillosis . In trichosporon PCR, Trichosporon 26S rRNA encoding gene was amplified from two strains of Trichosporon species, and detected by the nested PCR in 64 % of serum samples of patients with trichosporonosis, while glucuronoxylomannan antigen was detected in 55 % of samples . The high sensitivity and specificity of the nested PCR indicate that the assay can provide early diagnosis with sufficient accuracy to be clinically useful for patients with opportunistic fungal infection.

Mol Med Today, 1998 Oct, 4(10), 426 - 30
Is infection with Chlamydia pneumoniae a causative agent in atherosclerosis?
Kuo C, Campbell LA.
There is mounting evidence to suggest that Chlamydia pneumoniae might play a role in atherosclerosis . Serological studies and detection of the microorganism in atheromatous lesions were the first indications of an association between C . pneumoniae and the disease . Studies suggest that anti-chlamydial chemotherapy has a favorable effect on cardiovascular disease in humans . Moreover, infection of animals with C . pneumoniae induces inflammatory changes in the aorta that are suggestive of atherosclerosis and accelerates the progression of existing atherosclerotic lesions . If the pathogenic role of C . pneumoniae in atherosclerosis is defined more conclusively by future studies, the development of preventive or therapeutic measures against infection might provide an effective strategy to reduce the risk of atherosclerosis.

Rev Med Interne, 1998 Sep, 19(9), 658 - 60
{Endogenous infectious endophthalmitis}; Le Thi Huong D et al.; INTRODUCTION: Endogenous endophthtalmitis is an intraocular infection of hematogenous origin . EXEGESIS: It is generally a panuveitis that may be mixed-up with a non-infectious inflammatory disease, promoting delayed treatment and compromising the visual prognosis, as the visual loss rate reaches up to 37.5% . Antibiotherapy should be started immediately after bacteriological examinations and without waiting for vitrectomy . Identification of the causative microorganism is absolutely necessary . It may require aqueous or vitreous culture if cultures from other body fluids are negative and infection progresses . The most common infections are endocarditis and digestive and renal diseases . Virectomy is indicated for first line treatment of ocular abcess and improvement of antibiotic absorption . However, it may lead to retinal detachment . Vitrectomy is also indicated in case of unsuccessful therapy . To decrease the inflammatory reaction and risks of vitreous organization, local or systemic corticotherapy is prescribed after control of the infection . CONCLUSION: Although rare, endogenous endophthalmitis should be diagnosed as it may be mixed-up with inflammatory uveitis, leading to inappropriate corticotherapy . Furthermore, antibiotherapy with good intraocular penetration should be started immediately, but it should be kept in mind that the functional prognosis is poor.

Rev Argent Microbiol, 1998 Jul-Sep, 30(3), 147 - 53
{Presence of Mycoplasma in laboratory cell cultures from Cordoba, Argentina}; Cumino AC et al.; In this paper we determined the prevalence of mycoplasma contamination in 17 cell lines . Eighty per cent of the laboratories that currently use cell culture techniques participated in this study . Hoechst 33258 dye was used to detect mycoplasma contamination . The relationship between culture maintenance conditions and the presence of mycoplasma were analyzed, considering the use of antibiotics in the culture media, fetal calf serum (FCS) quality, culture media processing, use of disponsable labware, type of laminar flow cabinet, quantity of operators, and cell culture system . Thirty-five per cent of the analyzed cell lines showed mycoplasma contamination . Those lines belonged to 2 of the 8 surveyed laboratories . When confronting the working conditions versus mycoplasma contamination, 66% of the laboratories that employ non-certified FCS or reuse their labware, show mycoplasma contamination . Mycoplasma presence was found in 50% of the laboratories that use closed culture system, or more than one operator . Laboratories that process their culture media or that include antibiotic in the growing media, show a 40% contamination . The results obtained help to establish working conditions necessary to avoid introducing or spreading the microorganism.

FEMS Immunol Med Microbiol, 1998 Sep, 22(1-2), 185 - 9
Morphological and ultrastructural methods for Pneumocystis; Dei-Cas E et al.; Pneumocystis is a eukaryotic unicellular microorganism with marked fungal affinities . All known life cycle stages of this parasite were observed in the lung of mammals . The cystic forms of this microorganism may be observed microscopically by using stains with affinity for the components of their relatively thick cell wall . However, about 100 years ago they were observed for the first time thanks to panoptic stains which do not stain their cell wall . Methanol-Giemsa technique as well as Giemsa-like rapid stainings are often used to reveal vegetative or cystic forms of this parasite on air dried smears of clinical or experimental samples . For many years, hypotheses on its life cycle, which remains unknown, were based on transmission electron microscopy (TEM) studies . However, only for the last years progresses in the quality of fixation for TEM led to a better understanding of the Pneumocystis cell structure . In this chapter, strategies to reveal Pneumocystis organisms in clinical or experimental specimens by using light microscopy, as well as techniques allowing a good preparation of parasitic samples for TEM, are given and shortly discussed.

FEMS Immunol Med Microbiol, 1998 Sep, 22(1-2), 181 - 3
In vitro drug assays and statistical analysis; Atzori C et al.; The development of in vitro drug tests to assess the efficacy of drugs against Pneumocystis carinii has been hindered by the lack of efficient methods for continuous cultivation of the microorganism . However, different short-term culture systems have been proposed by many teams . In the present contribution an in vitro microplate drug assay and two statistical programs allowing the analysis of results are presented.

FEMS Immunol Med Microbiol, 1998 Sep, 22(1-2), 75 - 80
Epidemiological and taxonomic impact of Pneumocystis biodiversity; Mazars E et al.; A cluster of antigenic, genomic, karyotypic, isoenzymatic and morphological differences have been reported among Pneumocystis populations . Multilocus enzyme electrophoresis revealed strong linkage disequilibrium suggesting that Pneumocystis genotypes from different hosts have been genetically isolated from each other for a very long time . At least in some cases, genetic diversity is associated with phenotypic differences as revealed by in vitro, ultrastructural and cross infection studies . Thus, biodiversity in Pneumocystis has obvious epidemiological implications . Cross infection experiments revealed that Pneumocystis host species-related genetic differences are associated with close host species specificity, which suggests that transmission cannot take place between hosts of different species and that immunocompromised patients contract the infection primarily from infected humans . But these affirmations do not preclude other reservoirs for human pneumocystosis and research has to be extended to natural populations of synanthropic or wild mammals . Transmission of human pneumocystosis was also approached by typing human Pneumocystis isolates from patients or carriers, which should allow the follow up of parasite strains in human populations . As the strains of Pneumocystis found in different host species were considered for a long time to be morphologically indistinguishable, only one species of Pneumocystis was accepted for almost one century . At present, the scientific community is progressively accepting that the terminology 'P . carinii' is hiding a heterogeneous group of microorganisms . As available data made it impossible to establish if genetic divergence derives from clonal reproduction or speciation, no new species names have been attributed to Pneumocystis populations, but a trinomial nomenclature, including the Latin name of the host, was adopted in 1994 . It has to be outlined finally that works on biodiversity of Pneumocystis populations are basically important as they have revealed a new group of eukaryotic, pathogenic, heterogeneous microorganisms with fungal affinities, difficult to cultivate until now and widely spread in ecosystems . These researches are opening a virgin field for microbiology research.

Biochem Biophys Res Commun, 1998 Oct 29, 251(3), 759 - 62
Cloning of the novel gene intelectin, which is expressed in intestinal paneth cells in mice; Komiya T et al.; Using a large-scale in situ hybridization screening method, we isolated the cDNA gene intelectin, whose mRNA is expressed in small intestinal paneth cells in mice . Northern blot analysis revealed that the mRNA corresponding to the cDNA was 1.2 kp in length, and expression was specific to the tissue in the small intestine . We termed this gene intelectin because the deduced amino acid sequence is similar to the previously cloned oocyte lectin gene of Xenopus laevis . The function of intelectin may be involved in the defence of microorganisms .

Acta Vet Scand, 1998, 39(2), 201 - 13
The effect of prednisolone on canine neutrophil function: in vivo and in vitro studies; Trowald-Wigh G et al.; The in vivo effect of a therapeutic dose of prednisolone on canine neutrophil adherence, random migration, chemotaxis, phagocytosis of IgG and C3b opsonized yeast cells, chemiluminescence, Fc- and CR3-receptor expression was investigated . Prednisolone was also added in vitro to neutrophils as isolated cells and in whole blood . In the in vivo study, prednisolone increased the IgG mediated ingestion of yeast cells and the number of activated neutrophils in the phagocytosis assay, while flow cytometric investigation of the IgG-receptor Fc gamma RIII with a monoclonal antibody showed similar expression before, during and after treatment . Prednisolone also increased the ingestion of C3b-opsonized yeast cells, while the expression of CR3-receptors (CD11b CD18) measured by flow cytometry was unchanged . Chemiluminescence and the chemotactic response towards zymosan activated serum were increased, while adherence to nylon wool was decreased . The in vitro studies revealed that prednisolone had no or a dampening effect on neutrophils in cell suspensions . Adherence as well as IgG mediated ingestion was decreased at the highest prednisolone concentration (800 ng/ml) in whole blood . The present study suggests that the part of the antiinflammatory effect of corticosteroids mediated through their influence on neutrophils, besides reduced adherence, may be exerted by increased clearance of microorganisms and IgG-complexes through an elevated functional capacity.

Acta Vet Scand, 1998, 39(2), 173 - 82
Aerobic bacterial flora of semen and stallion reproductive tract and its relation to fertility under field conditions; Malmgren L et al.; This study was initiated in order to investigate the bacterial flora of the stallion genital tract by taking consecutive samples from normal stallions in regular use . The objective was to determine whether any growth of potential pathogens, particularly P . aeruginosa and K . pneumoniae, in fresh semen and urethra was associated with the presence of inflammatory cells in the semen and whether bacterial growth had any effect on sperm morphology and pregnancy results . Sixteen stallions, only used for A.I., housed at 3 different commercial stud farms, were used . A wide variety of microorganisms was found in almost all samples from fresh semen (total 115 samples) . P . aeruginosa was isolated from 46/115 (40%) of the samples and from 12 of the 16 stallions . K . pneumoniae was isolated from the semen of one stallion . Samples taken from the distal urethra after ejaculation contained fewer microorganisms than samples from fresh semen . No bacteria were found in 51% of the extended semen samples . Most of the stallions had an acceptable sperm morphology, and very few of the ejaculates contained inflammatory cells . Pregnancy results among the stallions varied, but were acceptable for most of them . There was no correlation between the frequency of samples testing positive for P . aeruginosa in raw semen and pregnancy results.

Ugeskr Laeger, 1998 Oct 5, 160(41), 5935 - 8
{Spontaneous and postoperative spondylodiscitis . A material concerning 23 patients}; Hansen SE et al.; A retrospective study of 23 patients with spondylodiscitis is reported . Sixteen cases were spontaneous . Five of these were seen in the acute phase with S . aureus grown from the blood . Eleven patients were investigated with CT-guided biopsy of the spine with identification of different microorganisms in eight cases . In four of seven cases of spondylodiscitis after operation for disc herniation coagulase-negative staphyloccoci were grown after CT-guided biopsy . In spontaneous cases pain disappeared and CRP was normalized within a few weeks after treatment with antibiotics, but radiological changes might progress for several months . Antibiotics were given for two to six months, with a mean of 5.1 months in purulent bacterial infections, and all patients were considered cured after this.

Infect Immun, 1998 Nov, 66(11), 5337 - 43
Invasion of aortic and heart endothelial cells by Porphyromonas gingivalis; Deshpande RG et al.; Invasion of host cells is believed to be an important strategy utilized by a number of pathogens, which affords them protection from the host immune system . The connective tissues of the periodontium are extremely well vascularized, which allows invading microorganisms, such as the periodontal pathogen Porphyromonas gingivalis, to readily enter the bloodstream . However, the ability of P . gingivalis to actively invade endothelial cells has not been previously examined . In this study, we demonstrate that P . gingivalis can invade bovine and human endothelial cells as assessed by an antibiotic protection assay and by transmission and scanning electron microscopy . P . gingivalis A7436 was demonstrated to adhere to and to invade fetal bovine heart endothelial cells (FBHEC), bovine aortic endothelial cells (BAEC), and human umbilical vein endothelial cells (HUVEC) . Invasion efficiencies of 0.1, 0.2, and 0 . 3% were obtained with BAEC, HUVEC, and FBHEC, respectively . Invasion of FBHEC and BAEC by P . gingivalis A7436 assessed by electron microscopy revealed the formation of microvillus-like extensions around adherent bacteria followed by the engulfment of the pathogen within vacuoles . Invasion of BAEC by P . gingivalis A7436 was inhibited by cytochalasin D, nocodazole, staurosporine, protease inhibitors, and sodium azide, indicating that cytoskeletal rearrangements, protein phosphorylation, energy metabolism, and P . gingivalis proteases are essential for invasion . In contrast, addition of rifampin, nalidixic acid, and chloramphenicol had little effect on invasion, indicating that bacterial RNA, DNA, and de novo protein synthesis are not required for P . gingivalis invasion of endothelial cells . Likewise de novo protein synthesis by endothelial cells was not required for invasion by P . gingivalis . P . gingivalis 381 was demonstrated to adhere to and to invade BAEC (0.11 and 0.1% efficiency, respectively) . However, adherence and invasion of the corresponding fimA mutant DPG3, which lacks the major fimbriae, was not detected . These results indicate that P . gingivalis can actively invade endothelial cells and that fimbriae are required for this process . P . gingivalis invasion of endothelial cells may represent another strategy utilized by this pathogen to thwart the host immune response.

Extremophiles, 1998 Aug, 2(3), 313 - 9
Life on Mars: chemical arguments and clues from Martian meteorites; Brack A et al.; Primitive terrestrial life-defined as a chemical system able to transfer its molecular information via self-replication and to evolve-probably originated from the evolution of reduced organic molecules in liquid water . Several sources have been proposed for the prebiotic organic molecules: terrestrial primitive atmosphere (methane or carbon dioxide), deep-sea hydrothermal systems, and extraterrestrial meteoritic and cometary dust grains . The study of carbonaceous chondrites, which contain up to 5% by weight of organic matter, has allowed close examination of the delivery of extraterrestrial organic material . Eight proteinaceous amino acids have been identified in the Murchison meteorite among more than 70 amino acids . Engel reported that L-alanine was surprisingly more abundant than D-alanine in the Murchison meteorite . Cronin also found excesses of L-enantiomers for nonprotein amino acids . A large collection of micrometeorites has been recently extracted from Antarctic old blue ice . In the 50- to 100-micron size range, carbonaceous micrometeorites represent 80% of the samples and contain 2% of carbon, on average . They might have brought more carbon than that involved in the present surficial biomass . The early histories of Mars and Earth clearly show similarities . Liquid water was once stable on the surface of Mars, attesting the presence of an atmosphere capable of deccelerating C-rich micrometeorites . Therefore, primitive life may have developed on Mars as well and fossilized microorganisms may still be present in the near subsurface . The Viking missions to Mars in 1976 did not find evidence of either contemporary or past life, but the mass spectrometer on the lander aeroshell determined the atmospheric composition, which has allowed a family of meteorites to be identified as Martian . Although these samples are essentially volcanic in origin, it has been recognized that some of them contain carbonate inclusions and even veins that have a carbon isotopic composition indicative of an origin from Martian atmospheric carbon dioxide . The oxygen isotopic composition of these carbonate deposits allows calculation of the temperature regime existing during formation from a fluid that dissolved the carbon dioxide . As the composition of the fluid is unknown, only a temperature range can be estimated, but this falls between 0 degree and 90 degrees C, which would seem entirely appropriate for life processes . It was such carbonate veins that were found to host putative microfossils . Irrespective of the existence of features that could be considered to be fossils, carbonate-rich portions of Martian meteorites tend to have material, at more than 1000 ppm, that combusts at a low temperature; i.e., it is an organic form of carbon . Unfortunately, this organic matter does not have a diagnostic isotopic signature so it cannot be unambiguously said to be indigenous to the samples . However, many circumstantial arguments can be made to the effect that it is cogenetic with the carbonate and hence Martian . If it could be proved that the organic matter was preterrestrial, then the isotopic fractionation between it and the carbon is in the right sense for a biological origin.

Extremophiles, 1998 Aug, 2(3), 239 - 48
Improvement of organic solvent tolerance level of Escherichia coli by overexpression of stress-responsive genes; Aono R; Water-immiscible organic solvents can be toxic to microorganisms . The tolerance levels differ among strains of Escherichia coli, suggesting that the organic solvent tolerance level is strain specific and determined genetically . We constructed several mutants from E . coli, of which the organic solvent tolerance levels were improved . The mutants were defective in the marR gene encoding a repressor protein for the mar operon that is responsible for environmental stress factors . High expression of stress-responsive genes, soxS, marA, and robA, elevated organic solvent tolerance levels of several strains of E . coli . These genes code for DNA-binding proteins that are transcriptional activators belonging to the AraC subfamily with the helix-turn-helix motif . It was shown that expression of the AcrAB-TolC system, a major efflux pump in E . coli, was positively regulated by the proteins . This system was highly expressed in the organic solvent-tolerant mutants . Strains defective in one of the genes, acrA, acrB, or tolC, were remarkably sensitive to organic solvents.

Extremophiles, 1998 Aug, 2(3), 201 - 5
Sugar utilization and its control in hyperthermophiles; de Vos WM et al.; Many hyperthermophilic microorganisms show heterotrophic growth on a variety of carbohydrates . There has been considerable fundamental and applied interest in the utilization of glucose and its alpha- and beta-polymers by hyperthermophiles . While glycolysis by Bacteria at high temperatures shows conventional characteristics, it has been found that glucose catabolism by hyperthermophilic Archaea differs from the canonical glycolytic pathways, involves novel enzymes, and shows a unique control . This review addresses these aspects with specific attention to Pyrococcus furiosus, which is one of the best studied hyperthermophilic Archaea, has the capacity to grow on a variety of sugars including the marine beta-(1,3)-linked glucose polymer laminarin, and has been found to contain three novel glycolytic enzymes, two ADP-dependent kinases, and a ferredoxin-dependent glyceraldehyde-3-phosphate oxidoreductase.

Extremophiles, 1998 Aug, 2(3), 149 - 54
Mechanisms of gene expression controlled by pressure in deep-sea microorganisms; Nakasone K et al.; A pressure-regulated operon has been cloned and sequenced from deep-sea barophilic Shewanella strains . To understand pressure-regulated mechanisms of gene expression, a regulatory element upstream of the pressure-regulated operon from Shewanella sp . strain DSS12 was studied . Regions A and B were classified by sequence analysis . A unique octamer motif, AAGGTAAG, was found to be repeated in tandem 13 times in region B . An electrophoretic mobility shift assay demonstrated that a O54-like factor recognizes region A and other unknown factors recognize region B . Different shift patterns of the protein-DNA complexes were observed when extracts of cells cultured at 0.1 MPa or 50 MPa were incubated with a DNA probe specific for region B . These results indicate that the deep-sea strain DSS12 expresses different DNA-binding factors under different pressure conditions.

Microbiology, 1998 Sep, 144 ( Pt 9), 2459 - 67
Fluorescence in situ hybridization shows spatial distribution of as yet uncultured treponemes in biopsies from digital dermatitis lesions; Moter A et al.; Fluorescence in situ hybridization (FISH) was performed on sections of plastic-embedded tissue using 16S rRNA-directed oligonucleotide probes to visualize uncultured treponemes in skin biopsies of cows with digital dermatitis . Plastic as embedding material allowed sectioning of hard and soft tissue with a defined thickness, avoiding the risk of dragging bacteria into the tissue while sectioning . furthermore, it provided a good signal-to-noise ratio . Using this method the spatial distribution of three different bacterial phylotypes was visualized simultaneously within the tissue . Whereas debris covering the ulcers contained a mixture of different micro-organisms, a layering of certain treponemal phylotypes was observed deeper in the epidermis . Confocal laser scanning microscopy and subsequent three-dimensional reconstruction of series of optical sections confirmed that the treponemes migrated intercellularly around the cells, most of them directed towards the dermis . In situ hybridization on tissue embedded in plastic proved to be a useful method to study mixed bacterial infections since it combines excellent histological conservation of tissue with identification of bacterial species by simultaneous use of probes labelled with different fluorescent dyes . This technique may have implications for in situ detection, identification and localization of microorganisms in veterinary as well as in human medicine.

Rev Prat, 1998 Mar 15, 48(6), 637 - 42
{Infections and lupus}; Le Moing V et al.; Infections are one of the major causes of morbidity and mortality during the course of systemic lupus erythematosus, and are promoted by various dysfunctions of the immune system, some of which are poorly understood . Other predisposing factors have been also identified such as the presence of glomerulonephritis and a treatment with high-dose corticosteroids or immunosuppressors . These factors have been particularly associated with the occurrence of opportunistic infections such as systemic candidiasis or Pneumocystis carinii pneumonia, whose frequency has increased with the intensity of therapeutic strategies . The most frequent infections encountered are induced by community-acquired microorganisms . Thus, initiating an empirical antibiotic treatment is justified in febrile patients with lupus erythematosus . In case of marked lymphopenia, it is recommended to start cotrimoxazole as primary prophylaxis against P . carinii pneumonia.

Rev Prat, 1998 Mar 1, 48(5), 513 - 8
{Methods and monitoring of antibiotic therapy of infectious endocarditis}; Besnier JM et al.; Antibiotic treatment of infective endocarditis has to be discussed when the microorganism has been identified . Antibiotics must be started as soon as possible, just after blood samplings in case of clinical bacteraemia, or as soon as blood cultures are positive . In case of negative blood cultures, diagnosis of endocarditis has to be reconsidered, according to Duke's criteria, and antibiotics must not be started until there is strong evidence in favour of infective endocarditis . Antibiotic treatment must be bactericidal, intravenously administered, for a long time to sterilize vegetations . Duration of antibiotics depends on the microorganism, and whether there is a valvular prosthesis or not . Hospitalization is often mandatory, but there is a trend towards the use of outpatient treatments, only possible in some indications.

Dev Neurosci, 1998, 20(4-5), 277 - 88
Landmarks in the application of 13C-magnetic resonance spectroscopy to studies of neuronal/glial relationships; Bachelard H; The development of the use of carbon isotopes as metabolic tracers is briefly described . 13C-labelled precursors (13CO2, 13CH4) first became available in 1940 and were studied in microorganisms, but their use was limited by very low enrichments and lack of suitable analytical equipment . More success was achieved with 11C and especially 14C, as these radioactive tracers did not need to be highly enriched . Although the stable 13C isotope can be used at a low percentage enrichment in mass spectrometry, its application to magnetic resonance spectroscopy (MRS) requires very highly enriched precursors, due to its low natural abundance and low sensitivity . Despite such limitations, however, the great advantage of 13C-MRS lies in its exquisite chemical specificity, in that labelling of different carbon atoms can be distinguished within the same molecule . Effective exploitation became feasible in the early 1970s with the advent of stable instruments, Fourier transform 13C-MRS, and the availability of highly enriched precursors . Reports of its use in brain research began to appear in the mid-1980s . The applications of 13C isotopomer analysis to research on neuronal/glial relationships are reviewed . The presence of neighbouring 13C-labelled atoms affects the appearance of the resonances (splitting due to C-C coupling), and so allows for unique quantification of rates through different and possibly competing pathways . Isotopomer patterns in resonances labelled from a combination of {1-13C}glucose and {1, 2-13C2}acetate have revealed aspects of neuronal/glial metabolic trafficking on depolarization and under hypoxic conditions in vitro . This approach has now been applied to in vivo studies on inhibition of glial metabolism using fluoroacetate . The results confirm the glial specificity of the toxin and demonstrate that it does not affect entry of acetate . When the glial TCA cycle is inhibited, the ability of the glia to participate in the glutamate/glutamine cycle remains unimpaired, in that labelling of glutamine, which can only be derived from neuronal metabolism of glucose, persists . The results also confirmed earlier evidence that part of the GABA transmitter pool is derived from glial glutamine.

J Immunol, 1998 Oct 15, 161(8), 4211 - 9
Comparison of humoral immune responses elicited by DNA and protein vaccines based on merozoite surface protein-1 from Plasmodium yoelii, a rodent malaria parasite; Kang Y et al.; Immunization with DNA vaccines encoding relevant Ags can induce not only cell-mediated immune response but also humoral immune responses against pathogenic microorganisms in several animal models . Our previous results demonstrated that, when the C terminus (PyC2) of Plasmodium yoelii merozoite surface protein-1 (MSP-1), a leading vaccine candidate against erythrocytic stages of malaria, was expressed as a fusion protein (GST-PyC2) with glutathione S-transferase (GST), it elicited Ab-mediated protective immune responses in BALB/c mice . In our present study, we wished to examine the humoral responses to a DNA vaccine (V3) encoding GST-PyC2 . The GST-PyC2 expressed in V3-transfected Cos 7 cells was recognized by a protective monoclonal Ab to PyC2 (mAb302), although the secreted product had undergone N-linked glycosylation . When BALB/c mice were immunized with V3 plasmid, anti-PyC2 Abs were successfully induced . These Abs immunoprecipitated native PyMSP-1 protein and competed with mAb302 for binding to its epitope at a level similar to those elicited by GST-PyC2 protein immunization . However, these Abs had significantly lower titers and avidities, and different isotype profiles and protective capacities against a lethal erythrocytic stage challenge, than those resulting from immunization with GST-PyC2 protein . Most surprising was the finding that, in contrast to protein immunization, there was no significant increase in the avidity of either GST-specific or PyC2-specific IgG Abs during the course of DNA immunization . This suggests that there may be little or no affinity maturation of specific Abs during DNA immunization in this system.

Vet Hum Toxicol, 1998 Oct, 40(5), 297 - 305
A cluster of equine granulomatous enteritis cases: the link with aluminium; Fogarty U et al.; A cluster of 6 cases of equine granulomatous enteritis is described . Aluminium was demonstrated in the tissues and lesions of these horses and in the intimal bodies of intestinal vessels . The relationship between granulomatous lesions, aluminium, acidity and invading microorganisms, particularly parasites, is presented and discussed.

Trends Microbiol, 1998 Sep, 6(9), 354 - 8
Interdependence of mycobacterial iron regulation, oxidative-stress response and isoniazid resistance; Dussurget O et al.; Iron is an essential cofactor for vital functions in microorganisms . Bacterial pathogens have developed efficient iron-acquisition systems to counteract the defensive sequestration of iron by their hosts . In mycobacteria, the recently described protein, IdeR, negatively controls iron-uptake systems . This protein also has a role in the oxidative-stress response, as well as in resistance to the frontline antimycobacterial drug isoniazid.

Immunobiology, 1998 Aug, 199(2), 327 - 39
Mannose-binding lectin (MBL) in health and disease; Turner MW; Mannose-binding lectin (MBL) is the most intensively studied human collectin . It is recognized to be a versatile macro-molecule with many of the functional characteristics of IgM, IgG and Clq . In the presence of calcium the protein can bind to a wide spectrum of oligosaccharides through multiple lectin domains . Such binding to the repeating sugar arrays on microbial surfaces may result in direct uptake by one or more collectin receptors on phagocyte surface or may trigger the activation of a pro-serine protease complex (MASP 1 and MASP 2) leading to cleavage of C4 and C2 of the classical complement pathway . Although serum levels of MBL are normally rather low (1500 micrograms/litre) there is increasing evidence that the protein plays an important role in immune defence, particularly during the phase of primary contact with a microorganism . This is suggested by the observed association of an increased incidence of infections in individuals with structural mutations in exon 1 of the MBL gene . A cluster of such mutations in codons 52, 54 and 57 lead to secondary structural abnormalities of the collagenous triple helix and a failure to form biologically functional higher order oligomers . The codon 54 mutation has been identified in several Eurasian populations whereas the codon 57 mutation is characteristic of sub-Saharan populations . One intriguing paradox arising from the MBL genotyping studies is the observation that in many populations there are surprisingly high frequencies of either the codon 54 or codon 57 mutation, suggesting that there may be some biological advantage associated with absence of the protein . Nevertheless, various groups have reported either low serum levels of MBL or an increased frequency of the structural gene mutations in patients with suspected immunodeficiencies, those with frequent unexplained infections and those with systemic lupus erythematosus . There is also evidence that the rate of progression of AIDS in HIV positive men is faster in those with such mutations . A recently published study of a consecutive series of admissions to a paediatric unit suggests that children presenting with an infectious aetiology are significantly more likely to have a MBL mutation . Moreover, this association was independent of age . Prospective studies are underway to address the questions raised by these findings.

Immunobiology, 1998 Aug, 199(2), 200 - 7
Functional roles of the lung surfactant proteins SP-A and SP-D in innate immunity; Reid KB; The surfactant proteins SP-A and SP-D are known to play important roles in innate immunity in the lungs in the protection against a wide variety of potential pathogens, which include viruses, bacteria and fungi . Recognition of the pathogens is, in most cases, mediated by the Ca+2-dependent binding of the C-type lectin domains of SP-A, or SP-D, to carbohydrate structures on the surface of the microorganisms . This can cause agglutination of the pathogens and also possibly their enhanced killing and clearance by phagocytic cells which carry receptors for SP-A or SP-D . Both SP-A and SP-D are found in a number of other sites in the body, in various secretions, and therefore may play a wider protective role than was initially envisaged.

Immunobiology, 1998 Aug, 199(2), 165 - 89
Structural aspects of collectins and receptors for collectins; Hansen S et al.; The collectins are oligomeric molecules composed of C-type lectin domains attached to collagen regions via alpha-coiled neck regions . Five members of the collectins have been characterized . Mannan-binding lectin (MBL), conglutinin and collectin-43 (CL-43) are serum proteins produced by the liver . Lung surfactant protein A (SP-A) and lung surfactant protein D (SP-D) are mainly found in the lung, where they are synthesized by alveolar type II cells and secreted to the alveolar surface . The collectins are believed to play an important role in innate immunity . They bind oligosaccharides on the surface of a variety of microbial pathogens . After binding of the collectins to the microbial surface effector mechanisms such as agglutination, neutralizing or opsonization of the microorganisms for phagocytosis are initiated . SP-A and SP-D stimulate chemotaxis of phagocytes and once bound to the phagocytes, the production of oxygen radicals can be induced . In the case of MBL the opsonization can be further enhanced by complement activation via the MBLectin pathway while conglutinin interacts with the complement system by binding to the complement degradation product iC3b . A number of receptors and binding molecules interacting with the collectins are found on the membrane or in association with the membrane of various cells responsible for phagocytosis and clearance of microorganisms . This paper focus on the structural aspects of the collectins and the receptors for collectins.

J Med Entomol, 1998 Sep, 35(5), 839 - 44
Effects of sodium concentration on Aedes triseriatus (Diptera: Culicidae) and microorganisms in treeholes; Paradise CJ et al.; A 2-factor field microcosm experiment with 2 concentrations of sodium ({Na}) was performed with and without mosquitoes to test the hypothesis that Na is a limiting nutrient for the treehole mosquito, Aedes triseriatus (Say), at concentrations observed in the field . This experiment also tested the effects of both water {Na} and mosquito larvae on cohabiting treehole microorganisms . Female Ae . triseriatus emerging from microcosms with high-{Na} were significantly larger than females emerging from low-{Na} microcosms . There was no effect of {Na} on the size of males; however, males had higher body {Na} than females at both {Na} . Densities of protozoans were lower in the presence of mosquitoes, and densities of bacteria were lower at high than low {Na} . Water {Na} may affect mosquito populations by decreasing energy expenditures to obtain Na at higher {Na}, allowing for more allocation to growth . Males were not affected by the {Na}s tested here . This experiment agrees with field observations and other laboratory studies indicating that {Na} may affect populations of Ae . triseriatus under certain conditions.

Rev Med Interne, 1998 Aug, 19(8), 548 - 57
{Cutaneous signs of Rickettsia and related microorganisms}; Duval X et al.; INTRODUCTION: Rickettsiosis are emerging, life-threatening infectious diseases that are world-wide distributed and have various manifestations . Most of the time, skin involvement is the prominent feature of clinical manifestations . Clinicians must therefore be well aware of these various clinical pictures . CURRENT KNOWLEDGE AND KEY POINTS: Knowledge about rickettsial infections has recently improved due to either the identification of new vectors and reservoirs, the description of new systemic and cutaneous signs and symptoms, or the amelioration of diagnosis methods . Cutaneous manifestations mainly depend on the type of microorganism and on the host characteristics . In some cases, they are so typical that their only identification would lead to the diagnosis . FUTURE PROSPECTS AND PROJECTS: As growing population movements may lead to an increase in the disease incidence, detailed knowledge of clinical, particularly cutaneous, manifestations of rickettsiosis is required in order to improve both diagnosis and treatment . When identified, cutaneous manifestations of rickettsiosis allow the clinician to confirm rapidly the diagnosis, using polymerase chain reaction or immunofluorescence and to institute prompt and specific treatment, thus reducing unfavorable disease outcome.

Proc Natl Acad Sci U S A, 1998 Oct 13, 95(21), 12300 - 5
Protein thermostability above 100 degreesC: a key role for ionic interactions; Vetriani C et al.; The discovery of hyperthermophilic microorganisms and the analysis of hyperthermostable enzymes has established the fact that multisubunit enzymes can survive for prolonged periods at temperatures above 100 degreesC . We have carried out homology-based modeling and direct structure comparison on the hexameric glutamate dehydrogenases from the hyperthermophiles Pyrococcus furiosus and Thermococcus litoralis whose optimal growth temperatures are 100 degreesC and 88 degreesC, respectively, to determine key stabilizing features . These enzymes, which are 87% homologous, differ 16-fold in thermal stability at 104 degreesC . We observed that an intersubunit ion-pair network was substantially reduced in the less stable enzyme from T . litoralis, and two residues were then altered to restore these interactions . The single mutations both had adverse effects on the thermostability of the protein . However, with both mutations in place, we observed a fourfold improvement of stability at 104 degreesC over the wild-type enzyme . The catalytic properties of the enzymes were unaffected by the mutations . These results suggest that extensive ion-pair networks may provide a general strategy for manipulating enzyme thermostability of multisubunit enzymes . However, this study emphasizes the importance of the exact local environment of a residue in determining its effects on stability.

Proc Natl Acad Sci U S A, 1998 Oct 13, 95(21), 12153 - 7
The anti-angiogenic agent fumagillin covalently modifies a conserved active-site histidine in the Escherichia coli methionine aminopeptidase; Lowther WT et al.; Methionine aminopeptidase (MetAP) exists in two forms (type I and type II), both of which remove the N-terminal methionine from proteins . It previously has been shown that the type II enzyme is the molecular target of fumagillin and ovalicin, two epoxide-containing natural products that inhibit angiogenesis and suppress tumor growth . By using mass spectrometry, N-terminal sequence analysis, and electronic absorption spectroscopy we show that fumagillin and ovalicin covalently modify a conserved histidine residue in the active site of the MetAP from Escherichia coli, a type I enzyme . Because all of the key active site residues are conserved, it is likely that a similar modification occurs in the type II enzymes . This modification, by occluding the active site, may prevent the action of MetAP on proteins or peptides involved in angiogenesis . In addition, the results suggest that these compounds may be effective pharmacological agents against pathogenic and resistant forms of E . coli and other microorganisms.

Sci Total Environ, 1998 Aug 12, 219(1), 21 - 8
Adhesion of water-borne particulates on freshwater biota; Sansone U et al.; The retention of suspended particles transported by river flow on surfaces of freshwater plants is a potentially important process in the contamination of aquatic biota . Field experiments have been performed to test the role of benthic algae (periphyton) in trapping inorganic suspended solids transported by the river water and to discriminate between the caesium content of periphyton caused by the adherence of inorganic solids and by the active uptake inside the organisms . The contribution of caesium of suspended solids adhering to biotic surfaces was estimated by determining the scandium content (scandium method) . The scandium method was used because this element is geologically ubiquitous in soils and it is not taken up actively by plants and other organisms . The mass of suspended particles retained on the surfaces of microorganisms growing on submerged substrates were determined by comparing the scandium content of suspended material with that in algal communities . Neutron activation analysis was used as the analytical method for determination for both scandium, and caesium . The results indicate that the suspended particle fraction can contribute up to 80% of the caesium contamination of periphyton samples . Active caesium uptake and accumulation by aquatic biota represents the remaining 20% of the total caesium contamination.

Clin Infect Dis, 1998 Sep, 27(3), 627 - 33
Germs, Dr . Billings, and the theory of focal infection; Gibbons RV; Our understanding of infectious diseases continues to expand rapidly, and has led to the realization that microorganisms are responsible for, or at least contribute to, numerous diseases that were never before associated with infectious etiologies . However, a review of medical history reminds us that this is not so novel an idea . Not long after the widespread acceptance of bacteriology and the germ theory and with an increased awareness of public hygiene, there was a period during which it seemed that nearly all diseases would prove to be the result of infections . One popular proposal that championed such an idea was the theory of focal infection . This article reviews this theory by considering the key concepts and developments that likely inspired it, and examines the work of the theory's most visible proponent, Dr . Frank Billings.

Rev Cubana Med Trop, 1996, 48(2), 123 - 9
{Purification and proteic characterization of a Cuban strain of the hepatitis A virus}; Diaz Mendiondo BI et al.; The purification and protein characterization of one of the Cuban isolated strains of hepatitis A virus was carried out . For this, it was necessary to separate the virus from the infected cell by extraction steps with detergents, concentration by ultrafiltration and finally, ultracentrifugation in saccharosoglycerol discontinuous gradient . Protein concentration, as well as the antigenic activity in the different fractions of the gradient were determined . For the protein characterization of the microorganism, those fractions with the greatest specific activity were analyzed by polyacrylamide gel electrophoresis and by Western blotting . It was shown that the viral material was purified and concentrated in the last fractions of the gradient . Bands corresponding to the structural proteins of hepatitis A were observed through electrophoresis and Western blotting.

Curr Microbiol, 1998 Nov, 37(5), 319 - 23
Lateral and perpendicular interaction forces involved in mobile and immobile adhesion of microorganisms on model solid surfaces; Busscher HJ et al.; Gliding and near-surface swimming of microorganisms are described as a mobile form of microbial adhesion that need not necessarily be reversible . It is argued that the reversibility of microbial adhesion depends on the depth of the secondary interaction minimum, calculated from the forces between an organism and a substratum acting in a direction perpendicular to the substratum surface . The mobility of adhering microorganisms depends on lateral interactions between the organisms . On ideally homogeneous and smooth model surfaces, only mobile adhesion occurs because the multibody, lateral interactions are weak compared with the thermal or Brownian motion energy of the organisms . Minor chemical or structural heterogeneities, which exist on all real-life surfaces, yield a lateral interaction on adhering microorganisms . This causes their immobilization, which helps to explain the physicochemical nature of microbial gliding or near-surface swimming . Moreover, these lateral interaction energies are one order of magnitude smaller than the Lifshitz-Van der Waals, electrostatic, and acid-base forces acting perpendicular to substratum surfaces that are responsible for adhesion.

Hematol Cell Ther, 1998 Aug, 40(4), 167 - 9
Severe infection caused by Stomatococcus mucilaginosus in a neutropenic patient: case report and review of the literature; Gruson D et al.; A 24-year-old female, in neutropenic phase after chemotherapy for acute myelogenous leukemia (on day 15) was admitted in intensive care unit for infectious pneumonia . Two strains of Stomatococcus mucilaginosus were isolated from peripheral blood cultures . No microorganisms were yielded from bronchoalveolar lavage . Patient's condition improved with prompt instigation of effective antibiotic therapy . This was the first case of septicemia and pneumonia, due to Stomatococcus mucilaginosus, in our unit . Only 26 cases occurring in neutropenic patients with underlying hematologic malignancies were reported in the literature and among these, only five cases with pneumonia were described . The complications of this normal inhabitant of the human oral cavity can be serious and fatal: septic shock, meningitis, acute respiratory distress syndrome . This study illustrate the possible virulence of Stomatococcus mucilaginosus in neutropenic patients.

Science, 1998 Oct 9, 282(5387), 281 - 4
Isolation of acidophilic methane-oxidizing bacteria from northern peat wetlands; Dedysh SN et al.; Acidic northern wetlands are an important source of methane, one of the gases that contributes to global warming . Methane oxidation in the surface of these acidic wetlands can reduce the methane flux to the atmosphere up to 90 percent . Here the isolation of three methanotrophic microorganisms from three boreal forest sites is reported . They are moderately acidophilic organisms and have a soluble methane monooxygenase . In contrast to the known groups of methanotrophs, 16S ribosomal DNA sequence analysis shows that they are affiliated with the acidophilic heterotrophic bacterium Beijerinckia indica subsp . indica.

Am J Dent, 1998 Jan, 11 Spec No, S45 - 54
The disastrous effects of the "total etch" technique in vital pulp capping in primates; Pameijer CH et al.; PURPOSE: To determine by means of a histopathological study in sub-human primates whether etching of an exposed pulp (the "Total Etch" technique) followed by capping with dentin bonding agents is a viable clinical treatment modality . MATERIALS AND METHODS: In six sub-human primates, 147 Class V preparations were made for five experimental and two control groups . After exposing the pulps, the preparations were intentionally contaminated, rinsed, dried and then disinfected with a 2% chlorhexidine solution for 60 s . In the five experimental groups, the entire preparation including the exposed pulp was etched with a 35% phosphoric acid gel, which was rinsed after 20 s . This was followed by a second application of chlorhexidine . In Groups 1-3, All Bond 2, ProBond and Permagen A&B dentin bonding agents were applied as pulp capping materials . In Group 4, a light-cured calcium hydroxide was tested while Group 5 was treated with a chemically-cured calcium hydroxide . Groups 6 and 7, the controls, were also contaminated, rinsed, dried and disinfected . After the exposed pulps had been protected with a chemically-cured calcium hydroxide (Group 6) or a light-cured calcium hydroxide (Group 7) the preparations were etched and restored with a bonded resin composite . The effect of the above described treatments were evaluated at 5, 25 and 75 days . After sacrifice and routine histological preparation, histological sections were graded among other parameters for inflammatory response, bridge formation, maintenance of vitality, presence of dentin chips and evidence of microleakage microorganisms . RESULTS: The 2% chlorhexidine applied immediately after exposure was an effective hemostatic agent . After subsequent etching, the hemostatic effectiveness was greatly reduced . Exposure size for all seven groups ranged from 0.13-1.55 mm . The average at 5, 25 and 75 days measured 0.74, 0.66 and 0.77 mm, respectively . In the five experimental groups, the 25- and 75-day groups had a total of 68 teeth of which 24 (35%) became non-vital and 23 (33%) teeth demonstrated bridge formation . In the three experimental groups using a bonding agent, the 25- and 75-day groups had a total of 40 teeth of which 18 (45%) became non-vital and 10 (25%) exhibited bridge formation . In the "No Etch" control groups, the 25- and 75-day groups had 28 teeth of which two (7%) became non-vital and 23 (82%) exhibited bridge formation . Microorganisms were found in a large percentage of all groups, although their numbers were few . However, they were present in vital and non-vital teeth, in the presence and absence of bridge formation and had no direct bearing on the success or failure of the pulp capping procedure.

Appl Environ Microbiol, 1998 Oct, 64(10), 3759 - 64
Toxic effects of modified fenton reactions on xanthobacter flavus FB71
Buyuksonmez F, Hess TF, Crawford RL, Watts RJ.
The toxic effects of modified Fenton reactions on Xanthobacter flavus FB71, measured as microbial survival rates, were determined as part of an investigation of simultaneous abiotic and biotic oxidations of xenobiotic chemicals . A central composite, rotatable experimental design was developed to study the survival rates of X . flavus under various concentrations of hydrogen peroxide and iron(II) and at different initial cell populations . A model based on the experimental results, relating microorganism survival to the variables of peroxide, iron, and cellular concentrations was formulated and fit the data reasonably well, with a coefficient of determination of 0.76 . The results of this study indicate that the use of simultaneous abiotic and biotic processes for the treatment of xenobiotic compounds may be possible.

Ital J Gastroenterol Hepatol, 1998 Jun, 30(3), 338 - 44
Current concept of the role of monocytes/macrophages in inflammatory bowel disease--balance of proinflammatory and immunosuppressive mediators; Lugering N et al.; Macrophages are important in providing the first line of intestinal defence against microorganisms or toxins that break the epithelial barrier, by presenting antigen to sensitised T cells and releasing a variety of cytokines and inflammatory mediators . During active states in inflammatory bowel disease, large numbers of monocytes leave the bloodstream and migrate into the inflamed mucosa and submucosa . Phenotypic studies have previously shown the presence of much more marked macrophage heterogeneity in inflammatory bowel disease mucosa than in normal mucosa . In both Crohn's disease and in ulcerative colitis, distinct macrophage populations have been found, being prominent in active disease, but absent from normal mucosa . Studies in our institution have shown that the Ca(2+)-binding proteins MRP8 and MRP14 as well as their heterocomplex MRP8/14 (27E10 epitope) are expressed in the majority of granulocytes and macrophages in active but not inactive inflammatory bowel disease . Furthermore, a strong complex MRP8/14 immunoreactivity was present in epithelial cells of the terminal ileum adjacent to ulcerative and fissuring lesions, while epithelial cells of large bowel tissues were consistently negative . In vitro studies revealed that interleukin-13, interleukin-10 and interleukin-4 strongly suppress secretion of different monocytic proteins . A combination of TH2-cytokines even at suboptimal concentrations significantly suppressed protein secretion, much more than using interleukin-13, interleukin-10 or interleukin-4 at a double concentration alone . Our morphological findings demonstrate the presence of MRP8/14 (27E10 antigen) both in monocytes/macrophages and in epithelial cells in active inflammatory bowel disease . Systemic or topical application of combined cytokine treatment might be a new effective therapeutic approach for chronic inflammatory bowel disease especially in those cases in which monocytes/macrophages lose their ability to respond, to some degree, to anti-inflammatory cytokines.

Biotechnol Prog, 1998 Sep-Oct, 14(5), 672 - 9
Modeling and analysis of co-immobilized aerobic/anaerobic mixed cultures; Tartakovsky B et al.; Systems of co-immobilized microorganisms are highly effective for conducting two or more consecutive bioprocesses within close proximity of the source and the sink of substrates . In this work, a general model of a co-immobilized aerobic/anaerobic bacterial system was developed and analyzed . The model was used to optimize pellet design and to study the effect of slow cell growth on process efficiency . The analysis demonstrated that co-immobilization of bacterial species accelerates the rate of biotransformation and provides complete transformation of toxic intermediates.

Curr Med Chem, 1998 Oct, 5(5), 391 - 419
Biosynthetic anthracyclines; Arcamone F et al.; This review summarizes the structure, the occurrence and the available data concerning the bioactivity of biosynthetic anthracyclines . The anthracyclines represent an important family of natural products produced by microorganisms of Streptomyces and related genera and include clinically useful agents for the medical treatment of human cancer . Chemically, the anthracyclines are glycosides characterized by a quinone tetracyclic aglycone and one or more deoxysugar units, mostly belonging to the L-hexopyranoside series, comprising generally an aminosugar . The different compounds belonging to this family are structurally related as they share a common biosynthetic pathway . Although some statements concerning structure activity relationships and molecular requirements for activity can be made, published data are not adequate for the comparative evaluation of potential antitumor efficacy of biosynthetic anthracyclines . This family of natural products is therefore still open for pharmacological investigation.

Scand J Work Environ Health, 1998 Aug, 24(4), 255 - 61
Meta-analyses of non-Hodgkin's lymphoma and farming; Khuder SA et al.; OBJECTIVES: This study examined the association between non-Hodgkin's lymphoma (NHL) and farming . METHODS: A series of meta-analyses of peer-reviewed studies was performed using 36 studies published between 1982 and 1997 . Prior to the meta-analyses, all the studies were reviewed and evaluated for heterogeneity and publication bias . Combined relative risks (RR) were calculated using the random effect model . RESULTS: The combined RR was 1.10 {95% confidence interval (95% CI) 1.03-1.19} for all the studies and 0.93 (95% CI 0.82-1.06) for studies involving female farmers . Significant heterogeneity was detected for study design and country of study among the studies . Significantly elevated RR values were obtained for case-referent studies (combined RR 1.19, 95% CI 1.06-1.33) and for studies conducted on farmers residing in the United States (combined RR 1.26, 95% CI 1.15-1.37) . These findings were not influenced by a publication bias . CONCLUSIONS: The findings suggest that male farmers residing in the United States have a slightly elevated risk of contracting NHL . Commonly experienced exposures that might contribute to the occurrence of NHL in this group include infectious microorganisms, herbicides, and insecticides.

Arch Latinoam Nutr, 1998 Mar, 48(1), 52 - 7
{Lipoxygenase and trypsin inhibitor inactivation in soymilk processing by direct milling and ultra high temperature (DM-UHT)}; Geronazzo H et al.; Soymilk production by a new process based on Direct Milling of soy grits and Ultra High Temperature (DM-UHT) has been studied at laboratory scale in order to evaluate solids and protein extraction, lipoxygenases (LO) and Trypsin Inhibitors (TI) inactivation during milling and heat-treatment steps . For TI measurements in soy extracts and soymilk a modification of the classical Kakade method (17) was used . Highest extraction yields were accomplished at 70 degrees C and 2 minutes milling of soy grits . LO was appreciably inactivated when using, as dispersing medium for milling, 0.01M sodium carbonate (Residual Activity 14%) instead of water (Residual Activity 46%), so in this way lower levels of undesired substances can be generated . LO destruction in the resulting suspension was finished by a short heating (30 seconds) from 70 degrees C to boiling temperature (96 degrees C) . On the other hand, TI were not fully inactivated in milling nor even in the steaming step at 96 degrees C for many minutes . The TI were inactivated to the accepted levels for soymilk in the final UHT step at 135 degrees C and 2 minutes, being possible at the same time to carry out the simultaneous microorganisms destruction.

Proc Natl Acad Sci U S A, 1998 Sep 29, 95(20), 11691 - 6
v-SNARE-dependent secretion is required for phagocytosis; Hackam DJ et al.; Phagosomes are generally believed to form by gradual apposition of the plasma membrane of leukocytes onto the surface of invading microorganisms . The internalization of the encapsulated particle is therefore predicted to reduce the surface area of the phagocyte . Contrary to this prediction, we observed that phagocytosis is associated with a net increase in cell surface area, suggesting the concomitant occurrence of exocytosis . Selective cleavage of components of the secretory machinery by microinjection or transfection of bacterial neurotoxins induced a pronounced inhibition of phagocytosis . These observations indicate that vesicle-soluble N-ethylmaleimide-sensitive factor attachment protein receptor-mediated exocytosis of endomembranes is essential for optimal completion of particle internalization during phagocytosis.

Proc Natl Acad Sci U S A, 1998 Sep 29, 95(20), 11514 - 9
Drug concentration heterogeneity facilitates the evolution of drug resistance; Kepler TB et al.; Pathogenic microorganisms use Darwinian processes to circumvent attempts at their control through chemotherapy . In the case of HIV-1 infection, in which drug resistance is a continuing problem, we show that in one-compartment systems, there is a relatively narrow window of drug concentrations that allows evolution of resistant variants . When the system is enlarged to two spatially distinct compartments held at different drug concentrations with transport of virus between them, the range of average drug concentrations that allow evolution of resistance is significantly increased . For high average drug concentrations, resistance is very unlikely to arise without spatial heterogeneity . We argue that a quantitative understanding of the role played by heterogeneity in drug levels and pathogen transport is crucial for attempts to control re-emergent infectious disease.

Chem Biol, 1998 Sep, 5(9), R221 - 33
The deoxyxylulose phosphate pathway of terpenoid biosynthesis in plants and microorganisms; Eisenreich W et al.; Recent studies have uncovered the existence of an alternative, non-mevalonate pathway for the formation of isopentenyl pyrophosphate and dimethylallyl pyrophosphate, the two building blocks of terpene biosynthesis.

Prikl Biokhim Mikrobiol, 1998 Jul-Aug, 34(4), 403 - 9
{Simplified model of increase in colony diameter during growth of unicellular microorganisms and its use in evaluating the effect of biocides on microbial cells}; Rodin VB et al.; A simplified model of increase in colony diameter is proposed . The model uses the size of single cells and several measurements of colony diameter during linear growth for calculating with good approximation the growth curve for the culture from the moment of inoculation . The parameter mu(m)', which is approximately 10% lower than the maximum specific growth rate of the colony biomass, could be also calculated . The effect of copper sulfate on the colony growth of Pseudomonas sp . G-1 was studied using the model . A high concentration of Cu2+ ions was found to result in decreases in the value of mu(m)', colony diameter, and the rate of increase in the colony diameter.

Prikl Biokhim Mikrobiol, 1998 Jul-Aug, 34(4), 339 - 53
{Physiologo-biochemical characteristics if Gluconobacter oxydans and prospects for its use in biotechnology and biosensor systems (review)}; Lusta KA et al.; Gluconobacter oxydans possesses a unique organization of metabolic systems, which are characterized by reduction of major dissimilation pathways, surface localization of main oxidative enzymes responsible for partial oxidation of carbon substrates, high performance of electron-transport chains, and accumulation of partially oxidized metabolites in the medium . These features allow us to use the cells of these microorganisms in biotechnology for production of several food products and medicines . The use of G . oxydans in biosensors for estimation of concentrations of sugars, aldoses and polyalcohols is promising . Physiological and biochemical features of these microorganisms enabling their use in biotechnology and receptor elements of biosensors are reviewed.

Epidemiol Mikrobiol Imunol, 1998 Aug, 47(3), 103 - 20
{Tularemia, "volume" two}; Macela A; As a continuation of Libich's monograph (Tularemie . Prague, Avicenum 1981) the author presents findings assembled in experiments pertaining to postinfectious immunity on a model of intracellular infection with the microorganism Francisella tularensis.

Trends Microbiol, 1998 Aug, 6(8), 328 - 35
Interactions between Mycobacterium tuberculosis and host cells: are mycobacterial sugars the key?
Ehlers MR, Daffe M.
Mycobacterium tuberculosis has evolved successful strategies to invade and persist within macrophages . Intimate pathogen-macrophage contacts dictate receptor choice and probably specify the intracellular fate of these microorganisms . Binding to specific receptors, such as complement receptor type 3, could provide an advantage . These interactions appear to involve surface polysaccharides and glycolipids.

Trends Microbiol, 1998 Aug, 6(8), 319 - 23
Segregation of minichromosomes in trypanosomes: implications for mitotic mechanisms; Gull K et al.; In addition to 11 pairs of housekeeping chromosomes, the genome of Trypanosoma brucei contains approximately 100 minichromosomes that are probably involved in the ability of the parasite to evade the host's immune response . This minichromosomal population is segregated on the mitotic spindle . How this is achieved provides insight into potential segregation mechanisms for small DNA molecules in eukaryotic microorganisms.

Trends Microbiol, 1998 Aug, 6(8), 307 - 14
Structure, function and stability of enzymes from the Archaea; Danson MJ et al.; The Archaea include microorganisms growing in some of the most extreme environments on earth . Consequently, their cellular components are remarkably stable entities and have considerable potential in the biotechnology industry . Here, we review the structure of archaeal enzymes in the context of their ability to function at extremes of temperature, salinity, pH and pressure.

J Exp Med, 1998 Sep 21, 188(6), 1091 - 1103
Characterization of a hemoglobin protease secreted by the pathogenic Escherichia coli strain EB1; Otto BR et al.; Many pathogenic bacteria can use heme compounds as a source of iron . Pathogenic Escherichia coli strains are capable of using hemoglobin as an iron source . However, the mechanism of heme acquisition from hemoglobin is not understood for this microorganism . We present the first molecular characterization of a hemoglobin protease (Hbp) from a human pathogenic E . coli strain . The enzyme also appeared to be a heme-binding protein . Affinity purification of this bifunctional protein enabled us to identify the extracellular gene product, and to clone and analyze its gene . A purification procedure developed for Hbp allowed us to perform functional studies . The protein interacted with hemoglobin, degraded it and subsequently bound the released heme . These results suggest that the protein is involved in heme acquisition by this human pathogen . Hbp belongs to the so-called IgA1 protease-like proteins, as indicated by the kinetics of its membrane transfer and DNA sequence similarity . The gene of this protein appears to be located on the large pColV-K30 episome, that only has been isolated from human and animal pathogens . All these characteristics indicate that Hbp may be an important virulence factor that may play a significant role in the pathogenesis of E . coli infections.

Anaesthesist, 1998 Jul, 47(7), 538 - 56
{Anesthesia and perioperative immune function}; Bauer M et al.; Innate and acquired immunity plays a pivotal role in the host defense response . Pain, stress, necrotic tissue and invading microorganisms are known modulators of the complex immune response of patients undergoing major surgery . Anaesthesia itself or perioperative interventions of the anaesthesiologist may substantially alter the immune function with potential impact on the postoperative course . For instance, transfusion of allogenic blood and administration of dopamine or metoclopramide may interfere with immunity . Stress and pain are associated with immune tolerance, increased susceptibility to infection and tumor spreading in animal models . Thus, anaesthesia may--through modulation of the neurohumoral stress response--indirectly affect immunity of the surgical patient . In particular epidural anaesthesia and/or administration of epidural or spinal opioids seem to attenuate the stress response with beneficial effects on cellular and humoral immunity . In addition, anaesthetics, such as etomidate, propofol, or thiopentone and opioid analgesics may directly affect function of immune competent cells . However, these actions may only be apparent with high or supraclinical concentrations and/or long-term exposure . Regarding the latter, evidence suggests that long-term sedation using thiopentone in neurosurgical patients is paralleled by infectious complications in a dose-dependent manner . At present, no data are available regarding the significance of the observed alterations associated with various anaesthetic procedures of the incidence of postoperative complications associated with impaired immunity, such as infection or metastatic spreading in oncological surgery.

Andrologia, 1998 Aug-Sep, 30(4-5), 289 - 96
Adhesion molecules and matrix proteins on human spermatozoa; Glander HJ et al.; Ejaculated spermatozoa and spermatogenic cells express alpha- and beta-chains of beta 1, 3 and 4 integrins as well as their ligands fibronectin and laminin in an extended intra- and interindividual variation and in different patterns of location . The mRNA transcripts of these molecules were detectable by nested polymerase chain reaction in the spermatozoa . The conclusion of a functional competence of these adhesion molecules (AM) was supported by their relation to the results of the zona-free hamster oocyte penetration (HOP) test, the in vitro fertilization of human oocytes and cell attachment assays . AM labelling was influenced by the disintegration of the sperm plasma membrane, especially in seminal plasma, by progesterone, human follicular fluid and microorganisms, but was barely modified by sperm cryopreservation . Despite substantial advances in the knowledge about sperm adhesion molecules, many questions remain to be answered.

Mayo Clin Proc, 1998 Sep, 73(9), 865 - 72
Primary immunodeficiencies; Ten RM; The primary immunodeficiencies are congenital disorders that affect the function of the immune system . The result is an inadequate immune response to microorganisms, self-antigens, and tumor cells, which leads to increased susceptibility to infections, autoimmunity, or malignant disease . A substantial advance has been made in the understanding of the exact molecular mechanisms leading to primary immunodeficiencies; however, for some types, a specific genetic defect has not yet been determined . The life expectancy of patients with primary immunodeficiencies has increased considerably because of bone marrow transplantation and replacement therapies . Gene therapy has already been used for a particular type of immunodeficiency and is a promising alternative for the future management of many other types of primary immunodeficiencies . A better understanding of the genetic defects that lead to primary immunodeficiencies would result in the development of novel therapeutic strategies.

Ginecol Obstet Mex, 1998 Jul, 66, 277 - 83
{Risk of transmission of infectious diseases by transfusion}; Figueroa Damian R; In obstetric patients transfusion is a common procedure, it has many advantages but it also has severe risks . Since the observation that human immunodeficiency virus (HIV) infection is transmitted by transfusion, the number of preventive measures to reduce the infectious diseases transmission by this procedure has increased . The microorganisms that can be transmitted through transfusion include: human T lymphotropic virus (HTLV) I and II, hepatitis B virus, hepatitis C virus, hepatitis D virus, hepatitis G virus, HIV, cytomegalovirus, Treponema pallidum, Barucella sp, Toxoplasma gondii, Plasmodium sp, and Trypanosoma cruzi . The most important measure for reduce transfusion risks is the appropriate and careful use of this procedure . This article review transfusion's indication, describe the infectious diseases commonest transmitted by transfusion and analyze the preventive measures to put in practice.

Antimicrob Agents Chemother, 1998 Sep, 42(9), 2421 - 4
Pharmacokinetics of meropenem in critically ill patients with acute renal failure treated by continuous hemodiafiltration; Krueger WA et al.; The pharmacokinetics of meropenem were studied in nine anuric critically ill patients treated by continuous venovenous hemodiafiltration . Peak levels after infusion of 1,000 mg over 30 min amounted to 103.2 +/- 45.9 microgram/ml, and trough levels at 12 h were 9.6 +/- 3.8 microgram/ml . A dosage of 1,000 mg of meropenem twice a day provides plasma drug levels covering intermediately susceptible microorganisms . Further reductions of the dosage might be appropriate for highly susceptible bacteria or when renal replacement therapies with lower clearances are applied.

J Periodontol, 1998 Aug, 69(8), 899 - 910
Increased presence of interleukin-6 (IL-6) and IL-8 secreting fibroblast subpopulations in adult periodontitis; Dongari-Bagtzoglou AI et al.; Periodontitis is a chronic inflammation of the supporting structures of the dentition which constitutes one of the most common causes of adult tooth loss . While certain microorganisms have been associated with the onset of the disease process, the exact pathogenetic mechanisms underlying periodontal destruction are still poorly understood . We have tested the hypothesis that gingival fibroblasts from diseased sites contribute to pathogenesis by possessing a secretory phenotype characterized by an exuberant secretion of inflammatory mediators and cytokines . Of the cytokines and mediators tested, fibroblast IL-1beta and prostaglandin E2 (PGE2) secretion was not different between health and disease . However, we have shown that fibroblasts from periodontal lesions produce in vitro greater amounts of IL-6 and IL-8 constitutively than healthy controls . When fibroblasts were stimulated with a panel of endogenous or exogenous response modifiers, the magnitude of cytokine and mediator stimulation above constitutive levels did not differ between health and disease . A strong positive correlation was identified between IL-6 or IL-8 constitutive secretion levels in vitro and the in situ expression of these cytokines within the connective tissues from where these cells originated, indicating that the in vitro phenotype mirrors their in vivo function . Furthermore, we present evidence which indicates that increased cytokine secretion by fibroblasts in disease is due to an elevated proportion of subpopulations with higher cytokine secretory capacity . Finally, we demonstrated that cultures from diseased sites are composed of cells with higher levels of constitutive CD40 expression, which may contribute to the increased IL-6 and IL-8 secretory phenotype.

Rocz Panstw Zakl Hig, 1998, 49(1), 73 - 86
{Sensitivity to disinfectants of Candid albicans strains isolated from the hospital environment}; Tadeusiak B; In recent years an increase of the incidence of Candida infections caused mainly by C . albicans strains especially in high risk inpatients with neoplasms, decreased immunity, burns and after treatment with multiple antibiotics has been observed . Candida organisms are particularly dangerous for newborns being responsible for about 30% of septicaemia cases in newborns in intensive care units . Fungal infections can be endogenous in origin but exogenous infection sources occur in hospitals . The cause of the latter are errors in aseptic management and insufficiently disinfected medical instruments and equipment . The purpose of the study was a comparison of the sensitivity to disinfectants of C . albicans belonging to two laboratory strains C . albicans PZH and C . albicans ATCC 10231 used for the determination of concentrations of two disinfectants used . Besides that, this sensitivity was determined in 14 strains isolated from the patients and one from the circuit of dialysis solution supply to artificial kidney . The study was carried out by the qualitative suspension method, in which the cells in the fluid were subjected to the action of disinfectants, and by the carrier method in which the cells of the microorganisms were present on the surface of metal cylinders . By the suspension method the sensitivity was determined to chloramine T in concentrations from 5.0% to 0.001%, formalin from 10.0% to 0.25%, glutaraldehyde from 2.0% to 0.1%, Septyl from 3.5% to 0.25% . The exposure time was 5, 10, 15, 30 and 60 minutes . The tested strains differed in their sensitivity to the disinfectants used . The greatest interstrain differences were observed in the sensitivity to the disinfectants used . The greatest interstrain differences were observed in the sensitivity to chloramine T . The highest concentrations were tolerated by the strains isolated from the patients and from the artificial kidney circuit as well as by the standard strain ATCC 10231 . In the 10-minute exposure time accepted by us as comparison standard these strains were 200-time less susceptible to chloramine than the standard C . albicans PZH strain . Two strain isolated from the patients were tenfold as sensitivive . The sensitivity to the remaining tested disinfectants showed less evident differences . The sensitivity of the strains from the patients to formalin was similar to that of the standard PZH strain . A similar sensitivity was found to Septyl, with the exception of the strain from the artificial kidney circuit which was sevenfold less sensitive than the PZH strain . In the case of glutaraldehyde 9 strains from the patients and the ATCC 10231 strain were two or four times less sensitive than the PZH strain . No cross-sensitivity or tolerance to the disinfectants were noted in the study . Both standard strains were similarly sensitive to formalin, but the ATCC 10231 strain was less sensitive to Septyl, glutaraldehyde and chloramine T . In the experiment by the carrier method the effect was evidenced of the surface on the action of disinfectants . This was particularly evident in the case of chloramine T . Even in sensitive strains the disinfection parameters (concentration and exposure time) were significantly higher than in the suspension method . The least sensitive strains survived the effect of 5% chloramine during 2 hours of exposure . Septyl in the working concentration 2.5% at 10-minute exposure time disinfected all carriers with the exception of that carrying the strain isolated from the artificial kidney circuit, which survived 15% Septyl exposure during 10 minutes . The disinfectant Aldesan (2% glutaraldehyde) and formalin 8% killed all fungi during 10 minutes . The study shows that the sensitivity of C . albicans strains to disinfectants varies . For the assessment of the fungicidal action of disinfectants the standard test ATCC 10231 should be used since its sensitivity was similar to that of most strains from the patients and medical equipment . (ABSTRACT TRUNCATED)

J Virol, 1998 Oct, 72(10), 8257 - 63
Herpes simplex virus type 1 glycoprotein gC mediates immune evasion in vivo; Lubinski JM et al.; Many microorganisms encode proteins that interact with molecules involved in host immunity; however, few of these molecules have been proven to promote immune evasion in vivo . Herpes simplex virus type 1 (HSV-1) glycoprotein C (gC) binds complement component C3 and inhibits complement-mediated virus neutralization and lysis of infected cells in vitro . To investigate the importance of the interaction between gC and C3 in vivo, we studied the virulence of a gC-null strain in complement-intact and C3-deficient animals . Using a vaginal infection model in complement-intact guinea pigs, we showed that gC-null virus grows to lower titers and produces less severe vaginitis than wild-type or gC rescued virus, indicating a role for gC in virulence . To determine the importance of complement, studies were performed with C3-deficient guinea pigs; the results demonstrated significant increases in vaginal titers of gC-null virus, while wild-type and gC rescued viruses showed nonsignificant changes in titers . Similar findings were observed for mice where gC null virus produced significantly less disease than gC rescued virus at the skin inoculation site . Proof that C3 is important was provided by studies of C3 knockout mice, where disease scores of gC-null virus were significantly higher than in complement-intact mice . The results indicate that gC-null virus is approximately 100-fold (2 log10) less virulent that wild-type virus in animals and that gC-C3 interactions are involved in pathogenesis.

FEMS Microbiol Rev, 1998 Jun, 22(2), 79 - 103
Horizontal gene transfer from transgenic plants to terrestrial bacteria--a rare event?
Nielsen KM, Bones AM, Smalla K, van Elsas JD.
Today, 12 years after the first field release of a genetically modified plant (GMP), over 15,000 field trials at different locations have been performed . As new and unique characteristics are frequently introduced into GMPs, risk assessment has to be performed to assess their ecological impact . The possibilities of horizontal gene transfer (HGT; no parent-to-offspring transfer of genes) from plants to microorganisms are frequently evaluated in such risk assessments of GMPs before release into the field . In this review we indicate why putative HGT from plants to terrestrial (soil and plant associated) bacteria has raised concern in biosafety evaluations . Further, we discuss possible pathways of HGT from plants to bacteria, outline the barriers to HGT in bacteria, describe the strategies used to investigate HGT from plants to bacteria and summarize the results obtained . Only a few cases of HGT from eukaryotes such as plants to bacteria have been reported to date . These cases have been ascertained after comparison of DNA sequences between plants and bacteria . Although experimental approaches in both field and laboratory studies have not been able to confirm the occurrence of such HGT to naturally occurring bacteria, recently two studies have shown transfer of marker genes from plants to bacteria based on homologous recombination . The few examples of HGT indicated by DNA sequence comparisons suggest that the frequencies of evolutionarily successful HGT from plants to bacteria may be extremely low . However, this inference is based on a small number of experimental studies and indications found in the literature . Transfer frequencies should not be confounded with the likelihood of environmental implications, since the frequency of HGT is probably only marginally important compared with the selective force acting on the outcome . Attention should therefore be focused on enhancing the understanding of selection processes in natural environments . Only an accurate understanding of these selective events will allow the prediction of possible consequences of novel genes following their introduction into open environments.

Microbiol Mol Biol Rev, 1998 Sep, 62(3), 646 - 66
Growth kinetics of suspended microbial cells: from single-substrate-controlled growth to mixed-substrate kinetics; Kovarova-Kovar K et al.; Growth kinetics, i.e., the relationship between specific growth rate and the concentration of a substrate, is one of the basic tools in microbiology . However, despite more than half a century of research, many fundamental questions about the validity and application of growth kinetics as observed in the laboratory to environmental growth conditions are still unanswered . For pure cultures growing with single substrates, enormous inconsistencies exist in the growth kinetic data reported . The low quality of experimental data has so far hampered the comparison and validation of the different growth models proposed, and only recently have data collected from nutrient-controlled chemostat cultures allowed us to compare different kinetic models on a statistical basis . The problems are mainly due to (i) the analytical difficulty in measuring substrates at growth-controlling concentrations and (ii) the fact that during a kinetic experiment, particularly in batch systems, microorganisms alter their kinetic properties because of adaptation to the changing environment . For example, for Escherichia coli growing with glucose, a physiological long-term adaptation results in a change in KS for glucose from some 5 mg liter-1 to ca . 30 microg liter-1 . The data suggest that a dilemma exists, namely, that either "intrinsic" KS (under substrate-controlled conditions in chemostat culture) or micromax (under substrate-excess conditions in batch culture) can be measured but both cannot be determined at the same time . The above-described conventional growth kinetics derived from single-substrate-controlled laboratory experiments have invariably been used for describing both growth and substrate utilization in ecosystems . However, in nature, microbial cells are exposed to a wide spectrum of potential substrates, many of which they utilize simultaneously (in particular carbon sources) . The kinetic data available to date for growth of pure cultures in carbon-controlled continuous culture with defined mixtures of two or more carbon sources (including pollutants) clearly demonstrate that simultaneous utilization results in lowered residual steady-state concentrations of all substrates . This should result in a competitive advantage of a cell capable of mixed-substrate growth because it can grow much faster at low substrate concentrations than one would expect from single-substrate kinetics . Additionally, the relevance of the kinetic principles obtained from defined culture systems with single, mixed, or multicomponent substrates to the kinetics of pollutant degradation as it occurs in the presence of alternative carbon sources in complex environmental systems is discussed . The presented overview indicates that many of the environmentally relevant apects in growth kinetics are still waiting to be discovered, established, and exploited.

Microbiol Mol Biol Rev, 1998 Sep, 62(3), 636 - 45
Nutrient uptake by microorganisms according to kinetic parameters from theory as related to cytoarchitecture; Button DK; The abilities of organisms to sequester substrate are described by the two kinetic constants specific affinity, a degrees, and maximal velocity Vmax . Specific affinity is derived from the frequency of substrate-molecule collisions with permease sites on the cell surface at subsaturating concentrations of substrates . Vmax is derived from the number of permeases and the effective residence time, tau, of the transported molecule on the permease . The results may be analyzed with affinity plots (v/S versus v, where v is the rate of substrate uptake), which extrapolate to the specific affinity and are usually concave up . A third derived parameter, the affinity constant KA, is similar to KM but is compared to the specific affinity rather than Vmax and is defined as the concentration of substrate necessary to reduce the specific affinity by half . It can be determined in the absence of a maximal velocity measurement and is equal to the Michaelis constant for a system with hyperbolic kinetics . Both are taken as a measure of tau, with departure of KM from KA being affected by permease/enzyme ratios . Compilation of kinetic data indicates a 10(8)-fold range in specific affinities and a smaller (10(3)-fold) range in Vmax values . Data suggest that both specific affinities and maximal velocities can be underestimated by protocols which interrupt nutrient flow prior to kinetic analysis . A previously reported inverse relationship between specific affinity and saturation constants was confirmed . Comparisons of affinities with ambient concentrations of substrates indicated that only the largest a degreesS values are compatible with growth in natural systems.

Clin Genet, 1998 Jul, 54(1), 90 - 4
Infectious complications of propionic acidemia in Saudia Arabia; Al Essa M et al.; A retrospective study of 38 patients with propionic acidemia indicates a high frequency of infections; affecting 80% of such patients . The Saudi Arabian population studied is a product of consanguineous marriages, and presents with a severe phenotype . Most microorganisms implicated are unusual, which suggests an underlying immune deficiency . These frequent infections occur despite aggressive treatment with appropriate diets, carnitine and during acute episodes of the disease with metronidazole, which suggests a global effect of the disease on T and B lymphocytes as well as on the bone marrow cells . Any patient with propionic acidemia should be closely followed up for an intercurrent infection in association with acute metabolic decompensation.

J Environ Pathol Toxicol Oncol, 1998, 17(3-4), 217 - 20
Variation of selenium content in growing wild plants during vegetative period; Miladinovic D et al.; There is evidence that selenium (Se) is essential for humans, animals, and some species of microorganisms . This study examines the dynamics of the change of Se accumulation in some growing wild plants: Astragalus onobrychis var . Chlorocarpus (Gris.) Stoj . et Stef . (Leguminosae), Oxytropis pilosa (L.) DC., Salvia officinalis, L., and Simphytum ottomanum L . The influences of some ecological factors (Se content in soil, temperature, and rainfall) have also been surveyed . The Se content of plants from Serbia was 44.5 to 177.0 microg/kg of dry weight . Astragalus onobrychis var . Chlorocarpus (Gris.) Stoj . et Stef . (Leguminosae) accumulates the highest Se content in the blooming stage (161.3 microg/kg) . All soils studied were deficient in selenium (< 250 microg/kg) . We found a significant correlation between Se content in plants and in the soil (p = 0.88) . Rainfall has an influence on Se content in Oxytropis, Salvia, and Simphytum, but not in Astragalus . Our results suggest that Se cannot have a similar role in all plants examined.

J Environ Pathol Toxicol Oncol, 1998, 17(3-4), 189 - 97
Selenium content in sulfide ores from the Chalkidiki peninsula, Greece; Nicolaidou AE; Selenium (Se) was assessed in galena, sphalerite, and pyrite samples . These are components of mixed sulfide ores from the Olympias and Madem Lakkos-Mavres Petres deposits and the Skouries porphyry-copper deposit . We used atomic absorption spectroscopy (AAS) with a hydride generator system . The highest concentration of Se (516 ppm) was found in the fine-grained galena at the -135 level of the Olympias deposits . In the Madem Lakkos-Mavres Petres deposit, the highest concentration of Se (33 ppm) was found in the pyrites of the level 30 . The concentration of Se in the arsenopyrites and chalcopyrites is lower than the detection limit of the analytical method (< 100 ppb) . The concentrated chalcopyrite from the porphyry copper deposit at Skouries exhibits a significant Se content (average 200 ppm) in contrast to the chalcopyrite from the Olympias and the Madem Lakkos-Mavres Petres . Variations in the Se content of the sulfide minerals studied could be caused by redox-pH and/or temperature conditions, as well as by the difference in crystal structure . The Se found in the areas studied may positively affect the environment . Sulfide minerals are oxidized by microorganisms, infiltrate in the soil-water in the form of selenate or selenite ion, and directly or indirectly influence the human organism.

Proc Natl Acad Sci U S A, 1998 Sep 1, 95(18), 11008 - 13
A response regulator of cyanobacteria integrates diverse environmental signals and is critical for survival under extreme conditions; Schwarz R et al.; Microorganisms must sense their environment and rapidly tune their metabolism to ambient conditions to efficiently use available resources . We have identified a gene encoding a response regulator, NblR, that complements a cyanobacterial mutant unable to degrade its light-harvesting complex (phycobilisome), in response to nutrient deprivation . Cells of the nblR mutant (i) have more phycobilisomes than wild-type cells during nutrient-replete growth, (ii) do not degrade phycobilisomes during sulfur, nitrogen, or phosphorus limitation, (iii) cannot properly modulate the phycobilisome level during exposure to high light, and (iv) die rapidly when starved for either sulfur or nitrogen, or when exposed to high light . Apart from regulation of phycobilisome degradation, NblR modulates additional functions critical for cell survival during nutrient-limited and high-light conditions . NblR does not appear to be involved in acclimation responses that occur only during a specific nutrient limitation . In contrast, it controls at least some of the general acclimation responses; those that occur during any of a number of different stress conditions . NblR plays a pivotal role in integrating different environmental signals that link the metabolism of the cell to light harvesting capabilities and the activities of the photosynthetic apparatus; this modulation is critical for cell survival.

Mol Microbiol, 1998 Aug, 29(3), 671 - 5
Are minichromosomes valid model systems for DNA replication control? Lessons learned from Escherichia coli; Asai T et al.; Initiation of chromosome replication is a key event in the life cycle of any organism . Little is known, however, about the regulatory mechanisms of this vital process . Conventionally, the initiation mechanism of chromosome replication in microorganisms has been studied using plasmids in which an origin of chromosome replication has been cloned, rather than using the chromosome itself . The reason for this is that even bacterial chromosomes are so large that biochemical and genetic manipulations become difficult and cumbersome . Recently, the combination of flow cytometry and genetic methods, in which modifications of the replication origin are systematically introduced onto the chromosome, has made possible detailed studies of the molecular events involved in the control of replication initiation in Escherichia coli . The results indicate that requirements for initiation at the chromosomal origin, oriC, are drastically different from those for initiation at cloned oriC.

Naturwissenschaften, 1998 Jul, 85(7), 318 - 29
Pollution in the Baltic Sea; Rheinheimer G; The Baltic Sea is almost totally surrounded by land and therefore more endangered by pollution than other marine areas . The sources of marine pollution are municipal and industrial waste inputs directly into the sea or via rivers, and atmospheric inputs mainly from traffic and agriculture . The increase of inorganic plant nutrients (NH3, NOx, PO4) caused eutrophication and consequent oxygen depletion in coastal bottom waters as well as in the depths of the open sea . In the anoxic sediments, hydrogen sulfide can be produced by protein-decomposing and sulfate-reducing bacteria . The bottom fauna will be destroyed and only H2S tolerant microorganisms can survive . Originating from cellulose manufacturing and from paper mills, large amounts of poisonous chlorinated compounds contaminated the coastal waters of Sweden and Finland until the 1980s . Most of this material is still present in sediments of the central Baltic Sea and can be resuspended by near bottom currents . To reduce pollution and improve the situation in the Baltic Sea, the surrounding countries organized the Helsinki Convention, which came into force on 3.5.1980 . The Helsinki Commission (HELCOM) founded in 1974 acts as coordinator and is responsible for the enforcement of the Baltic monitoring program and international research projects . The activities of HELCOM have led to the reduction of dangerous pollutants which in turn has caused the regeneration of flora and fauna in some areas . Further improvements can be expected.

Genetica, 1998, 102-103(1-6), 109 - 25
Adaptive mutagenesis: a process that generates almost exclusively beneficial mutations; Hall BG; Adaptive mutations are spontaneous mutations that occur in microorganisms during periods of prolonged stress in non-dividing or very slowly dividing populations and that are specific to the environmental challenge that causes that stress . This article reviews the literature on adaptive mutagenesis since 1993 . The evidence that adaptive mutagenesis is both real and general is considered . The most widely used system for studying adaptive mutagenesis, reversion of an F'-borne lacI33 allele, is shown to be a special case that reflects more about F-plasmid biology than about adaptive mutagenesis in general . New evidence demonstrating that adaptive mutagenesis is, indeed, specific is discussed . A variety of genes whose products affect adaptive mutagenesis are discussed . A model to explain that specificity and new evidence in support of that model are considered, as are potential roles of adaptive mutagenesis in evolution and practical aspects of adaptive mutagenesis.

Electrophoresis, 1998 Jul, 19(10), 1521 - 4
In memory of Harry Rilbe: an outstanding scientist who made many valuable contributions to the development of electrophoretic methods; Vesterberg O; In July 1997 Professor Harry Rilbe passed away at the age of 84 . Harry Rilbe was an outstanding personality skilled in chemistry, optics and mathematics, and he will be remembered for his important contributions to the development of separation methods, notably moving boundary electrophoresis and isoelectric focusing . The latter method is used for analytical and preparative purposes in thousands of laboratories worldwide . Isoelectric focusing is indispensable for characterization of proteins from humans, animals, plants and microorganisms . Isoelectric focusing is thus useful for the understanding of the function of genes and, accordingly, for progress in the life sciences . A biographical retrospect, "A scientific life with chemistry, optics and mathematics", was published by Harry Rilbe in Electrophoresis 1984, 5, 1-17.

Immunobiology, 1998 Jul, 199(1), 148 - 51
The transcription factors c-myb and C/EBP alpha regulate the monocytic/myeloic gene MRP14; Klempt M et al.; The entry of microorganisms into the body induces inflammatory processes . During this process a sequence of cellular, humoral, non-specific and specific actions are evoked to combat the infection . Macrophages and granulocytes, which are developed from a common progenitor cell, are the cellular components of the specific and non-specific immunoreaction . MRP14 (Macrophage migration inhibitory related protein) and MRP8, two S-100 proteins contained in high concentrations in these cells are obviously essential for adhesion and migration of monocytes and granulocytes . To investigate the transcriptional regulation of these genes we cotransfected constructs expressing CAT under control of the MRP14 promoter and expression constructs of C/EBP alpha and v-myb, two transcription factors involved in myeloid/monocytic differentiation . Transfection with C/EBP alpha revealed a massive enhancement of the MRP14 promoter in both, HL 60 cells (granulocytic differentiated) and L132 fibroblasts . In contrast, v-myb reduces MRP14 promoter activity . Northern blot analysis of L132 cells transfected with the C/EBP alpha expression vector demonstrate that C/EBP alpha is sufficient to enhance MRP14 expression in the context of the whole genome.

Scand J Immunol, 1998 Aug, 48(2), 116 - 23
Reconstitution of opsonizing activity by infusion of mannan-binding lectin (MBL) to MBL-deficient humans; Valdimarsson H et al.; Mannan-binding lectin (MBL, previously named mannan-binding protein, MBP) is a serum collectin, which activates complement upon binding to microbial carbohydrates . This results in opsonization of the microorganisms as well as direct complement-mediated killing . Clinical evidence indicates that MBL has an important role in the innate immune defence against various pathogens . Genetically determined MBL deficiency is associated with increased susceptibility to infections . We have infused two MBL-deficient individuals with clinical grade MBL, purified from pooled donor plasma, in doses sufficient to attain normal concentration of MBL in serum . This resulted in normalization of complement-mediated opsonization . An initial rapid decrease in the serum concentration of MBL was followed by a slower decline with an estimated half-life of about 6 days . No adverse effects were observed and anti-MBL antibodies could not be detected following several MBL infusions . One of the two MBL recipient, a two-year-old girl, who had been suffering from repeated infections from the age of 4 months, was given a total of six MBL infusions . She has subsequently remained healthy for more than three years.

J Parasitol, 1998 Aug, 84(4), 743 - 8
Isotype profiles of Leishmania donovani-infected BALB/c mice: preferential stimulation of IgG2a/b by liposome-associated promastigote antigens; Afrin F et al.; Leishmaniasis presents a complex spectrum of diseases and immunological manifestations depending upon both the species of the microorganism and the host it infects . BALB/c mice, which are homozygous for Lsh(s) on chromosome 1, are genetically susceptible to the visceralizing species of Leishmania . Infection of these mice with an Indian strain of Leishmania donovani showed a steady rise in the level of parasite burden in both the liver and the spleen to 24 wk . To investigate the immune responses determining the course of infection, we studied the relative levels of specific IgG, IgM, and IgA antibodies, and IgG isotypes, in the sera of diseased and protectively immunized mice at different periods of infection . IgG1 and IgG2a were stimulated in the control, infected, and immunized mice after parasite challenge . However, an early induction of IgG1 in the normal infected mice and stimulation of IgG2a and IgG2b isotypes prior to parasite challenge in liposome-antigen-immunized mice suggest that the elicitation of a particular subset of CD4+ T cells at the onset of disease may be responsible for either progression or resolution of infection.

Acta Gastroenterol Latinoam, 1998, 28(2), 203 - 8
{Exfoliative cytology for diagnosis of Helicobacter pylori}; Paniagua M et al.; The development of more reliable diagnostic methods has undoubtedly contributed to a better knowledge of the epidemiology and role of Helicobacter pylori (Hp) in the physiopathology of upper digestive tract diseases . Non abrasive and abrasive diagnostic methods have been used; among the latter, the exfoliating of abrasive cytology has been very popular during the last years . This fact motivated us to do this investigation . A descriptive-prospective study was developed in which the sample was composed by 235 patients of both sexes . The patients underwent gastro-duodenoscopy on account of dyspeptic symptoms and in order to determine the presence of Hp and its association with endoscopically diagnosed gastritis, with or without duodeno-gastric reflux, using the SYDNEY classification system . The frequency of Hp was assessed and the density of this microorganism was correlated with the hystological type of chronic gastritis following the above-mentioned classification . As a method of diagnosis of this disease, cytology showed a sensibility of 72% a specificity of 100% and an efficiency of 77% compared with histology, that was considered the "golden test" . It was histologically proved that there exists a close relationship between chronic gastritis and the presence of Hp in the gastric antrum and that when the density of the bacterial population increases, the severity of chronic gastritis increases too . This germ may show up in histologically normal mucose, being able to provoke dyspeptic symptoms and colonizing the gastric antrum independently of the presence of duodeno-gastric reflux.

Cell Mol Life Sci, 1998 Jul, 54(7), 628 - 40
Scavenger receptor family proteins: roles for atherosclerosis, host defence and disorders of the central nervous system; Yamada Y et al.; In this review, we summarize the structure and function of the scavenger receptor family of proteins including class A (type I and II macrophage scavenger receptors, MARCO), class B (CD36, scavenger receptor class BI), mucinlike (CD68/macrosialin, dSR-CI) and endothelial (LOX-1) receptors . Two motifs have been identified as ligand-binding domains: a charged collagen structure of type I and II receptors, and an immunodominant domain of CD36 . These structures can recognize a wide range of negatively charged macromolecules, including oxidized low-density lipoproteins, damaged or apoptotic cells, and pathogenic microorganisms . After binding, these ligands can be either internalized by endocytosis or phagocytosis, or remain at the cell surface and mediate adhesion or lipid transfer through caveolae . Under physiological conditions, scavenger receptors serve to scavenge or clean up cellular debris and other related materials, and they play a role in host defence . In pathological states, they mediate the recruitment, activation and transformation of macrophages and other cells which may be related to the development of atherosclerosis and to disorders caused by the accumulation of denatured materials, such as Alzheimer's disease.

Nippon Jibiinkoka Gakkai Kaiho, 1998 Jun, 101(6), 821 - 8
{Clinical features and characteristics of paranasal sinus effusion in allergic sinusitis}; Suzuki M et al.; Plain paranasal sinus radiographs including occipitofrontal and occipitomental views often show abnormal shadows in patients with allergic rhinitis . For that reason, the relationship between chronic sinusitis and allergy has been discussed for many years . Type I allergy is thought to be involved in the sinusitis which is called allergic sinusitis . However, there is not enough information pertaining to this disorder . In order to determine the clinical feature and the characteristics of paranasal sinus effusion in allergic sinusitis, we investigated the differences between 20 patients with allergic sinusitis and 20 with non-allergic chronic sinusitis used as controls . Clinical symptoms (nasal discharge, nasal obstruction, headache, postnasal discharge) and anterior rhinoscopic findings (nasal discharge, nasal edema), clinical examinations (type of x ray maxillary sinus shadow, bacteriology of nasal discharge), and pathological features of the paranasal sinus effusion were examined and compared in the two kind of sinusitis . Pathological findings of the effusion sampled from 14 patients with allergic sinusitis and 15 with non-allergic sinusitis included the number of eosinophils, activated eosinophils and neutrophils, concentrations of interleukin (IL)-1 beta, IL-4, IL-5, IL-8, and concentrations of leukotriene C4/D4/E4 and prostaglandin E2 . The incidence and degree of postnasal discharge as a symptom and a nasal finding were lower in allergic sinusitis patients than in the controls . Microorganisms were detected less frequently in the allergic group . The number of eosinophils, activated eosinophils and neutrophils was higher in the paranasal sinus effusion of the patients with allergic sinusitis . The concentrations (ng/mg of protein) of IL-1 beta and IL-8 showed no difference between the two groups, but IL-4, and IL-5 were more prevalent per mg of protein in the effusion of allergic sinusitis patients . These findings suggest that the clinical features of allergic sinusitis include a low incidence and degree of postnasal discharge and a low rate of detection of bacteria, and that the sinus effusion is characterized by the presence of more eosinophils, activated eosinophils, and IL-5 than in those of chronic sinusitis.

J Food Prot, 1998 Jun, 61(6), 725 - 7
Microbial stability of mango (Mangifera indica L.) juice preserved by combined application of mild heat and extracts of two tropical spices; Ejechi BO et al.; The microbial stability of mango (Mangifera indica L.) juice (pH 4.9) supplemented with extracts of ginger (Zingiber officinale) and nutmeg (Myristica fragrans) was investigated during 3 months of ambient-temperature storage . Heating at 55 degrees C for 15 min markedly reduced the levels of non-spore-forming bacteria and produced a product with acceptable taste . Supplementing mango juice with an agueous extract of ginger (15%, vol/vol) or nutmeg (20%, vol/vol) inhibited the growth of challenge microorganisms, but produced a product with unacceptable taste . Heating the mango juice at 55 degrees C for 15 min and supplementing with nutmeg (4%, vol/vol) markedly inhibited microbial growth and produced a product with acceptable taste . Tropical spices may prove useful in preservation of fruit juices by hurdle technology.

J Food Prot, 1998 May, 61(5), 633 - 6
Effect of lyophilization on the mechanical characteristics of a large particle and on the behavior of immobilized bacterial spores; Rodrigo F et al.; The mechanical stability of the carrier and the behavior of the sensor element of a time-temperature integrator (TTI) after lyophilization and storage for 60 days at room temperature were studied . The results indicated that particles containing added starch at concentrations from 2 to 12% had good handling characteristics for use as TTI carriers, although mechanical resistance was lower by comparison with freshly prepared particles . Lyophilization reduced the number of viable microorganisms by 17 to 25%, depending on the length of the storage period . Variations were also observed in the count of surviving microorganisms after heating at 121 degrees C for 12 min . These variations, expressed as decimal reductions in the number of microorganisms, might reflect an effect of lyophilization on the thermal resistance of the immobilized spores.

J Food Prot, 1998 May, 61(5), 582 - 5
Inactivation of microorganisms with microwaves at reduced temperatures; Kozempel MF et al.; We developed a pilot-plant nonthermal flow process using microwave energy to inactivate microorganisms . The process consists of multiple passes through the microwave generator . Each passed material goes to a receiving tank for subsequent passes . The flow rate was 0.96 to 1.26 kg/min and the dwell time per pass was 1.1 to 1.5 min . Five passes were used . The microwave energy is instantaneously and simultaneously applied to the system, and thermal energy is removed by a cooling tube within the process line in the microwave generator . The cooling tube maintains the temperature below 40 degrees C . There was significant reduction in microorganisms in water, 10% glucose solution, and apple juice, and in yeast in beer . There was a slight decrease in microorganisms in tomato juice, pineapple juice, apple cider, and beer; and no effect in skim milk.

FEBS Lett, 1998 Jul 17, 431(2), 241 - 4
Biological significance of the side chain length of ubiquinone in Saccharomyces cerevisiae; Okada K et al.; Ubiquinone (UQ), an important component of the electron transfer system, is constituted of a quinone structure and a side chain isoprenoid . The side chain length of UQ differs between microorganisms, and this difference has been used for taxonomic study . In this study, we have addressed the importance of the length of the side chain of UQ for cells, and examined the effect of chain length by producing UQs with isoprenoid chain lengths between 5 and 10 in Saccharomyces cerevisiae . To make the different UQ species, different types of prenyl diphosphate synthases were expressed in a S . cerevisiae COQ1 mutant defective for hexaprenyl diphosphate synthesis . As a result, we found that the original species of UQ (in this case UQ-6) had maximum functionality . However, we found that other species of UQ could replace UQ-6 . Thus a broad spectrum of different UQ species are biologically functional in yeast cells, although cells seem to display a preference for their own particular type of UQ.

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